R 语言语法特点

R语言常用语法

1、R语言创建向量和矩阵

（1）、c()

用c()来创建一个向量

例：创建向量x1与x2

> x1 = c(1,3,5,7,9)
> x1
    [1] 1 3 5 7 9
> x2 = c(0,2,4,6,8)
> x2
    [1] 0 2 4 6 8
>

（2）、length()

用length()来求一个向量的长度

例：

> length(x1)
    [1] 5
> length(x2)
    [1] 5
>

（3）、mode()

用mode()来显示数据类型

例：

> mode(x1)
    [1] "numeric"
> mode(x2)
    [1] "numeric"
>

基本数据结构类型有：

numeric 数值型
complex 复数型
character 字符型
logical 逻辑型

（4）、rbind()

用rbing()可以把x1和x2以行的形式组合成矩阵

例：

> rbind(x1,x2)
    [,1] [,2] [,3] [,4] [,5]
    x1    1    3    5    7    9
    x2    0    2    4    6    8
>

（5）、cbind()

用cbing()可以把x1与x2以列的形式组合成矩阵

例：

cbind(x1,x2)
x1 x2
[1,] 1 0
[2,] 3 2
[3,] 5 4
[4,] 7 6
[5,] 9 8

2、R语言求平均值、和、连乘、最值、方差、标准差

函数为：mean(),sum(),prod(),min(),max(),var(),sd()

例：1:100是指1到100公差为1的等差数列

在R语言中，区分大小写

mean(x)求平均值

例：

> x = c(1:10)
> x
[1]  1  2  3  4  5  6  7  8  9 10
> mean(x)
[1] 5.5
>

sum(x)求和

例：

> sum(x)
[1] 55
>

prod(x)求连乘

例：

> prod(x)
[1] 3628800
>

min(x)求最小值

例：

> min(x)
[1] 1
>

max(x)求最大值

例：

> max(x)
[1] 10
>

var(x)求方差

例：

> var(x)
[1] 9.166667
>

sd(x)求标准差

例：

> sd(x)
[1] 3.02765
>

3、帮助函数help()

例：

help()

4、操作向量

（1）显示1到10公差为1的数列

> 1:10

（2）数列都减1后显示

> 1：10-1

（3）数列先乘以2再加上1后显示

2：10*2+1

（4）先赋值后显示

> x3 = 2:10*2+1
> x3

（5）显示下标为3的数

> 3[3]

（6）下标为3的不显示

> x3[-3]

（7）显示下标为1到3的数

> x3[1:3]

（8）下标为1到3的数不显示

>x3[-(1:3)]

（9）显示下标为1，3，5的数

> x3[c(1,3,5)]

（10）把元素值小于10的数显示出来

> x3[x3<10]

（11）把元素值大于10小于15的数显示出来

> x3[x3>10 & x3<15]

（12）把x3[2]的数显示出来

> x3[x3[2]]

5、seq()函数

（1）显示1到20且公差为1的数

> seq(1,20)

（2）显示1到20且公差为2的数

> seq(1,20,by=2)

（3）显示3到10的3个数,相当于对线段3到10进行3-1等分

> seq(3,10,length=3)

6、letters()函数

产生字母序列
例：

> letters[1:30]

7、which()函数

> which.max(a)显示最大数的最后一个的下标

> which.min(a)显示最小数的最后一个的下标

> a=c(2,3,5,4,9,7,5,3,1,2,5,4,2,3)
> a[ which.max(a)]

> a[ which.min(a)]显示数列中最小的数

> a[which.max(a)]显示数列中最大的数

> which(a==2)显示数据为2的下标

> a[which(a==2)]

> which(a>5)显示数据大于5的下标

> a[which(a>5)]

8、rev()函数

rev()函数可以向量颠倒

9、sort()函数

sort()函数可以使数据从小到大排列

10、生成矩阵

函数matrix()
nrow表示行，ncol表示列，且排列是按列的顺序时行排，且byrow默认为false,为true时表示为按行进行排列

11、矩阵运算

（1）、函数t()

函数t()的作用相当于行列置换

（2）、矩阵加减

矩阵加减要求行列相同

（3）、矩阵相乘

> a%*%b

（这个没有计算是否正确，简单的二阶相乘，谁想测可以测一下，求证）

（4）、函数diag()

求出方阵对角线的元素

diag(diag(x))表示对角线矩阵

diag(3)表示生成为3阶的单位矩阵

（5）、函数rnorm()

rnorm()函数表示以正太分布的形式产生随机数

（6）、solve()

solve()函数表示求逆矩阵

而且solve()函数可以解方程组

（觉得高数还可以，可以进行测试看看是否正确，求证）

12、矩阵的特征值与特征向量

函数eigen()可以求出矩阵的特征值和特征向量

R语言基础之语法

分支结构If…else…和 Ifelse()函数

Ifelse()函数是支持向量化计算的，ifelse(判断条件,为真的时候返回的变量,条件为假的时候返回的变量)。

举例

<code class="hljs ruby has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">> (<span class="hljs-constant" style="box-sizing: border-box;">Brand</span>=paste(c(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'Brand'</span>),<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span><span class="hljs-symbol" style="color: rgb(0, 102, 102); box-sizing: border-box;">:</span><span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span>,sep=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">''</span>))
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Brand1"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Brand2"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Brand3"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Brand4"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Brand5"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Brand6"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Brand7"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Brand8"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Brand9"</span>
> (<span class="hljs-constant" style="box-sizing: border-box;">PName</span>=paste(c(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'Dell'</span>),<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span><span class="hljs-symbol" style="color: rgb(0, 102, 102); box-sizing: border-box;">:</span><span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span>,sep=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">''</span>))
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Dell1"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Dell2"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Dell3"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Dell4"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Dell5"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Dell6"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Dell7"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Dell8"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Dell9"</span>
> (<span class="hljs-constant" style="box-sizing: border-box;">Men</span>=rep(c(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'1G'</span>,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'2G'</span>,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'4G'</span>),times=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>))
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"1G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"2G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"4G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"1G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"2G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"4G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"1G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"2G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"4G"</span>
> (<span class="hljs-constant" style="box-sizing: border-box;">Feq</span>=rep(c(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'2.2G'</span>,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'2.8G'</span>,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'3.3G'</span>),each=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>))
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"2.2G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"2.2G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"2.2G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"2.8G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"2.8G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"2.8G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"3.3G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"3.3G"</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"3.3G"</span>
> (<span class="hljs-constant" style="box-sizing: border-box;">Price</span>=rep(c(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1000</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5000</span>),<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>))
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5000</span>
> <span class="hljs-constant" style="box-sizing: border-box;">PC</span>=data.frame(<span class="hljs-constant" style="box-sizing: border-box;">Brand</span>,<span class="hljs-constant" style="box-sizing: border-box;">PName</span>,<span class="hljs-constant" style="box-sizing: border-box;">Men</span>,<span class="hljs-constant" style="box-sizing: border-box;">Feq</span>,<span class="hljs-constant" style="box-sizing: border-box;">Price</span>)
> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#初始化，先为每个电脑都先打上Cheap标签</span>
> <span class="hljs-constant" style="box-sizing: border-box;">PC</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">$PD</span> = rep(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'Cheap'</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span>)
> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (i <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">in</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span><span class="hljs-symbol" style="color: rgb(0, 102, 102); box-sizing: border-box;">:nrow</span>(<span class="hljs-constant" style="box-sizing: border-box;">PC</span>)){  <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#遍历PC数据框</span>
+   <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span>(<span class="hljs-constant" style="box-sizing: border-box;">PC</span>[i,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'Price'</span>]><span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3000</span>){
+     <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#当价格大于3000的时候，就改成Expensive</span>
+     <span class="hljs-constant" style="box-sizing: border-box;">PC</span>[i,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'PD'</span>]=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'Expensive'</span>
+   }
+ }
> <span class="hljs-constant" style="box-sizing: border-box;">PC</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#从输出结果来看，每个品牌的电脑，都被标定了价格。</span>
   <span class="hljs-constant" style="box-sizing: border-box;">Brand</span> <span class="hljs-constant" style="box-sizing: border-box;">PName</span> <span class="hljs-constant" style="box-sizing: border-box;">Men</span>  <span class="hljs-constant" style="box-sizing: border-box;">Feq</span> <span class="hljs-constant" style="box-sizing: border-box;">Price</span>        <span class="hljs-constant" style="box-sizing: border-box;">PD</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand1</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell1</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.2</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1000</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand2</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell2</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.2</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand3</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell3</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.2</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5000</span> <span class="hljs-constant" style="box-sizing: border-box;">Expensive</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand4</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell4</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.8</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1000</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand5</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell5</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.8</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand6</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell6</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.8</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5000</span> <span class="hljs-constant" style="box-sizing: border-box;">Expensive</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand7</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell7</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.3</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1000</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand8</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell8</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.3</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand9</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell9</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.3</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5000</span> <span class="hljs-constant" style="box-sizing: border-box;">Expensive</span>

> <span class="hljs-constant" style="box-sizing: border-box;">PC</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">$PD2</span>=ifelse(<span class="hljs-constant" style="box-sizing: border-box;">PC</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">$Price</span>><span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3000</span>,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'Expensive'</span>,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'Cheap'</span>) <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#用ifelse函数来实现相同的功能更方便</span>
> <span class="hljs-constant" style="box-sizing: border-box;">PC</span>
   <span class="hljs-constant" style="box-sizing: border-box;">Brand</span> <span class="hljs-constant" style="box-sizing: border-box;">PName</span> <span class="hljs-constant" style="box-sizing: border-box;">Men</span>  <span class="hljs-constant" style="box-sizing: border-box;">Feq</span> <span class="hljs-constant" style="box-sizing: border-box;">Price</span>        <span class="hljs-constant" style="box-sizing: border-box;">PD</span>       <span class="hljs-constant" style="box-sizing: border-box;">PD2</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand1</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell1</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.2</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1000</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand2</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell2</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.2</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand3</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell3</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.2</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5000</span> <span class="hljs-constant" style="box-sizing: border-box;">Expensive</span> <span class="hljs-constant" style="box-sizing: border-box;">Expensive</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand4</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell4</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.8</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1000</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand5</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell5</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.8</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand6</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell6</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.8</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5000</span> <span class="hljs-constant" style="box-sizing: border-box;">Expensive</span> <span class="hljs-constant" style="box-sizing: border-box;">Expensive</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand7</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell7</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.3</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1000</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand8</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell8</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.3</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>     <span class="hljs-constant" style="box-sizing: border-box;">Cheap</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span> <span class="hljs-constant" style="box-sizing: border-box;">Brand9</span> <span class="hljs-constant" style="box-sizing: border-box;">Dell9</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>G <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.3</span>G  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5000</span> <span class="hljs-constant" style="box-sizing: border-box;">Expensive</span> <span class="hljs-constant" style="box-sizing: border-box;">Expensive</span>

> <span class="hljs-constant" style="box-sizing: border-box;">PC</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">$Price</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#PC$Prince是一个向量ifelse能完成向量化计算，对每一个元素作比较返回相应的值。</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5000</span>
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li></ul>

循环结构

for循环

从向量x中取出单个数据存到临时变量n当中，每取出一次，就执行一次循环体。
for(n in x){
…
}

举例

<code class="hljs scss has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">> <span class="hljs-function" style="box-sizing: border-box;">for(x in <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>)</span>{
+   print (x^2)
+ }
<span class="hljs-attr_selector" style="color: rgb(0, 136, 0); box-sizing: border-box;">[1]</span> 1
<span class="hljs-attr_selector" style="color: rgb(0, 136, 0); box-sizing: border-box;">[1]</span> 4
<span class="hljs-attr_selector" style="color: rgb(0, 136, 0); box-sizing: border-box;">[1]</span> 9
<span class="hljs-attr_selector" style="color: rgb(0, 136, 0); box-sizing: border-box;">[1]</span> 16
<span class="hljs-attr_selector" style="color: rgb(0, 136, 0); box-sizing: border-box;">[1]</span> 25</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul>

while循环

condition为真的时候执行循环体
while(condition){
….
}

举例

<code class="hljs markdown has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-blockquote" style="box-sizing: border-box;">> i = 1</span>
<span class="hljs-blockquote" style="box-sizing: border-box;">> while(i<6){</span>
<span class="hljs-bullet" style="box-sizing: border-box;">+   </span>print (x^2)
<span class="hljs-bullet" style="box-sizing: border-box;">+   </span>i = i + 1
<span class="hljs-bullet" style="box-sizing: border-box;">+ </span>}
[1] 25
[1] 25
[1] 25
[1] 25
[1] 25</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li></ul>

repeat循环

repeat是死循环，只有用break来打断
repeat{
…
break
}

举例

<code class="hljs markdown has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-blockquote" style="box-sizing: border-box;">> i = 1</span>
<span class="hljs-blockquote" style="box-sizing: border-box;">> repeat{</span>
<span class="hljs-bullet" style="box-sizing: border-box;">+   </span>print (i^2)
<span class="hljs-bullet" style="box-sizing: border-box;">+   </span>i = i + 1
<span class="hljs-bullet" style="box-sizing: border-box;">+   </span>if (i>5) break
<span class="hljs-bullet" style="box-sizing: border-box;">+ </span>}
[1] 1
[1] 4
[1] 9
[1] 16
[1] 25</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li></ul>

break、next

break是终止整个循环
next是终止当前的循环，不执行循环体中next后面的部分。

函数和包

1、函数

向量、因子、矩阵、数据框、数组、列表以及函数都是一类对象，可以随时创建，可以作为函数的参数。也就是说，R语言中的函数因为是一类对象，所以可以在函数中再创造函数，在C语言和C++等语言中函数就不是一类对象，必须提前编译。

1）、创建

在R语言中，没有return语句的时候，会把整个函数的最后一句作为返回语句。

myfunction = function(par1,par2){
……
}

<code class="hljs javascript has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">> myadd = <span class="hljs-function" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">function</span><span class="hljs-params" style="color: rgb(102, 0, 102); box-sizing: border-box;">(a,b,c)</span>{</span>
+   <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> (a+b+c)
+ }
> (a = myadd(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>))
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul>

<code class="hljs markdown has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-blockquote" style="box-sizing: border-box;">> mystat = function(x,na.omit=FALSE){</span>
<span class="hljs-bullet" style="box-sizing: border-box;">+   </span>if (na.omit){
<span class="hljs-bullet" style="box-sizing: border-box;">+     </span>x=x[!is.na(x)] #是否忽略向量中的缺省值
<span class="hljs-bullet" style="box-sizing: border-box;">+   </span>}
<span class="hljs-bullet" style="box-sizing: border-box;">+   </span>m=mean(x)
<span class="hljs-bullet" style="box-sizing: border-box;">+   </span>n=length(x)
<span class="hljs-bullet" style="box-sizing: border-box;">+   </span>s=sd(x)
<span class="hljs-bullet" style="box-sizing: border-box;">+   </span>skew=sum((x-m)^3/s^3)/n
<span class="hljs-bullet" style="box-sizing: border-box;">+   </span>return (list(n=n,mean=m,stdev=s,skew=skew))
<span class="hljs-bullet" style="box-sizing: border-box;">+ </span>}
<span class="hljs-blockquote" style="box-sizing: border-box;">> x=rnorm(1000,100,10) #创建一个正太分布的随机向量，有1000个数，平均数是100，标准差是10</span>
<span class="hljs-blockquote" style="box-sizing: border-box;">> mystat(x)</span>
$n
[1] 1000

$mean
[1] 100.4087

$stdev
[1] 9.899276

$skew
[1] 0.03952049</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li></ul>

2）、查看函数代码

不带括号的函数名
使用page函数，打开编辑器查看代码。

<code class="hljs php has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">> mystat  <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#通过不带括号的函数名来调用</span>
mystat = <span class="hljs-function" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">function</span><span class="hljs-params" style="color: rgb(102, 0, 102); box-sizing: border-box;">(x,na.omit=FALSE)</span>{</span>
  <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (na.omit){
    x=x[!is.na(x)] <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#是否忽略向量中的缺省值</span>
  }
  m=mean(x)                 <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#调用mean()函数计算均值</span>
  n=length(x)               <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#调用length()函数计算长度</span>
  s=sd(x)                   <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#调用sa()函数计算标准差</span>
  skew=sum((x-m)^<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>/s^<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>)/n   <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#计算偏度系数 偏度系数是描述分布偏离对称性程度的一个特征数。当分布左右对称时，偏度系数为0。当偏度系数大于0时，即重尾在右侧时，该分布为右偏。当偏度系数小于0时，即重尾在左侧时，该分布左偏。</span>
  <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">list</span>(n=n,mean=m,stdev=s,skew=skew))
}
myadd = <span class="hljs-function" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">function</span><span class="hljs-params" style="color: rgb(102, 0, 102); box-sizing: border-box;">(a,b,c)</span>{</span>
  <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> (a+b+c)
}

>page(mystat) <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#使用page函数，调用系统的编辑器查看代码。</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li></ul>

3）、导入.R文件

<code class="hljs bash has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">source</span>(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'G:/TestFunction.r'</span>)</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>

2、包的安装和加载

1）、包的安装

R语言中包的安装会自动解决依赖

使用R自带的编辑器安装包

第一步、程序包 ————> 设定CRAN镜像
第二步、程序包 ————> 安装程序包

使用命令安装

install.packages(‘abc’)

2）、包的加载

安装包的时候需要用”将包的名称包裹，加载包的时候不需要。

Rstudio中使用命令加载包

<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">> library(abc)
载入需要的程辑包：abc.data
载入需要的程辑包：nnet
载入需要的程辑包：quantreg
载入需要的程辑包：SparseM

载入程辑包：‘SparseM’

The following <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">object</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">is</span> masked <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">from</span> ‘package:<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">base</span>’:

    backsolve

载入需要的程辑包：MASS
载入需要的程辑包：locfit
locfit <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.5</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9.1</span>   <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2013</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">03</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">22</span>
></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li></ul>

Rstudio中，使用右下角的面板来加载包。

直接勾选就好。

向量化计算

1、普通的加减乘除

所谓向量化运算就是对向量中的每一个元素都进行运算处理

举例

<code class="hljs markdown has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-blockquote" style="box-sizing: border-box;">> (x=1:5)</span>
[1] 1 2 3 4 5
<span class="hljs-blockquote" style="box-sizing: border-box;">> (x=x^2)</span>
[1]  1  4  9 16 25
<span class="hljs-blockquote" style="box-sizing: border-box;">> (y=matrix(1:20,4,5))</span>
<span class="hljs-code" style="box-sizing: border-box;">     [,1] [,2] [,3] [,4] [,5]</span>
[1,]    1    5    9   13   17
[2,]    2    6   10   14   18
[3,]    3    7   11   15   19
[4,]    4    8   12   16   20
<span class="hljs-blockquote" style="box-sizing: border-box;">> (y=y^2)</span>
<span class="hljs-code" style="box-sizing: border-box;">     [,1] [,2] [,3] [,4] [,5]</span>
[1,]    1   25   81  169  289
[2,]    4   36  100  196  324
[3,]    9   49  121  225  361
[4,]   16   64  144  256  400

<span class="hljs-blockquote" style="box-sizing: border-box;">> (y=11:15)</span>
[1] 11 12 13 14 15
<span class="hljs-blockquote" style="box-sizing: border-box;">> (x+y) #相同长度的向量可以直接+-*/</span>
[1] 12 16 22 30 40
<span class="hljs-blockquote" style="box-sizing: border-box;">> y>=13</span>
[1] FALSE FALSE  TRUE  TRUE  TRUE</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li></ul>

向量化运算支持哪些运算：+-*/等四则运算 >

2、apply家族

apply
sapply lapply
mapply tapply

1)、 apply(x,MARGIN=2,…)

apply(数组，维度，函数/函数名)

沿着数组的某一维度来处理数据，利用设置MARGIN的值来改变数据。MARGIN=2表示在列（域）的层面上处理数据

举例

<code class="hljs markdown has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-blockquote" style="box-sizing: border-box;">> x=data.frame(pv=rnorm(100,20,3), #先生成一个有三个域的数据框</span>
<span class="hljs-blockquote" style="box-sizing: border-box;">>            + uv=rnorm(100,40,4),</span>
<span class="hljs-blockquote" style="box-sizing: border-box;">>            + ip=runif(100,40,50))</span>
<span class="hljs-blockquote" style="box-sizing: border-box;">> apply(x,MARGIN = 2,mean)  #MARGIN=1表示在行（记录）层面上处理数据，MARGIN=2表示在列（域）的层面上处理数据。处理方式是，mean，求均值。</span>
<span class="hljs-code" style="box-sizing: border-box;">      pv       uv       ip </span>
20.45526 39.81572 45.30480
<span class="hljs-header" style="box-sizing: border-box;">#quantile是查看一组数据的百分位点，probs=c(0.1,0.5,0.9)设置想查看的百分位点</span>
<span class="hljs-blockquote" style="box-sizing: border-box;">> apply(x,MARGIN = 2,quantile,probs=c(0.1,0.5,0.9))  </span>
<span class="hljs-code" style="box-sizing: border-box;">          pv       uv       ip</span>
10% 16.90155 35.17513 41.02527
50% 20.09723 39.38737 45.19671
90% 24.70416 44.82648 49.37066
<span class="hljs-header" style="box-sizing: border-box;">#可以看到pv、uv、ip在0.1、0.5、0.9处的百分位点</span>

<span class="hljs-header" style="box-sizing: border-box;">#数据降维</span>
<span class="hljs-blockquote" style="box-sizing: border-box;">> (x=array(rnorm(2*3*4),c(2,3,4))) #生成一个三维的列表</span>
, , 1

<span class="hljs-code" style="box-sizing: border-box;">            [,1]      [,2]       [,3]</span>
[1,] -0.04255047 -1.407329 -0.9931210
[2,] -1.65621498  1.479997  0.5501781

, , 2

<span class="hljs-code" style="box-sizing: border-box;">           [,1]      [,2]       [,3]</span>
[1,] -0.4668323 0.7451938  0.9585998
[2,] -0.4205612 0.3414420 -1.1822220

, , 3

<span class="hljs-code" style="box-sizing: border-box;">          [,1]     [,2]        [,3]</span>
[1,]  0.596996 0.233922  0.03285836
[2,] -1.534795 1.598219 -1.89555578

, , 4

<span class="hljs-code" style="box-sizing: border-box;">           [,1]       [,2]      [,3]</span>
[1,]  0.6793028  0.4429203 -0.605179
[2,] -0.4042032 -0.6241099  1.257368

<span class="hljs-blockquote" style="box-sizing: border-box;">> apply(x,c(1,2),mean)  #将列表沿着3维的方向来处理数据，求均值。</span>
<span class="hljs-code" style="box-sizing: border-box;">          [,1]       [,2]       [,3]</span>
[1,]  0.191729 0.00367673 -0.1517105
[2,] -1.003944 0.69888709 -0.3175580
<span class="hljs-blockquote" style="box-sizing: border-box;">> apply(x,c(1,3),mean)  #将列表沿着2维的方向来处理数据，求均值。</span>
<span class="hljs-code" style="box-sizing: border-box;">           [,1]       [,2]       [,3]       [,4]</span>
[1,] -0.8143335  0.4123204  0.2879255 0.17234803
[2,]  0.1246534 -0.4204471 -0.6107106 0.07635149
<span class="hljs-blockquote" style="box-sizing: border-box;">> apply(x,c(2,3),mean)  #将列表沿着1维的方向来处理数据，求均值。</span>
<span class="hljs-code" style="box-sizing: border-box;">            [,1]       [,2]       [,3]        [,4]</span>
[1,] -0.84938273 -0.4436968 -0.4688996  0.13754980
[2,]  0.03633396  0.5433179  0.9160706 -0.09059479
[3,] -0.22147144 -0.1118111 -0.9313487  0.32609427

</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li></ul>

2)、 lapply(列表,函数名/函数,其他参数)

lapply总是返回一个列表

<code class="hljs lua has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">> (x=list(a=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>,b=c(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">21</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">31</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">41</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">51</span>))) #创建一个列表
$a
 [<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>

$b
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">21</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">31</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">41</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">51</span>

> lapply(x,mean)  #对列表的成分求均值，lappy返回值也是一个列表。
$a
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5.5</span>

$b
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">31</span>

> (x=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>)
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>

> lapply(x,runif) #runif函数是从均匀分布的总体中抽取若干个数字。runif函数一次作用于x中的每一个元素。
<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[1]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.1420802</span> #x=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>的时候抽出<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.1420802</span> 

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[2]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5706941</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5051777</span> #x等于<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>的时候，抽出两个数

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[3]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.9835877</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5630008</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.2712130</span> #x等于<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>的时候，抽出<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>个数

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[4]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.3299968</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.6336621</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.3345203</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.4135361</span> #x等于<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>的时候，抽出<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>个数

> lapply(x,runif,min=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>,max=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">100</span>)
<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[1]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.9995915</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[2]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17.17236</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">85.43321</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[3]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">95.25653</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">52.58847</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">48.70183</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[4]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">79.50202</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">96.41646</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">56.94763</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">38.45675</span>

> lapply(x,runif,min=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>,max=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">100</span>)  #min=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>,max=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">100</span>是作用于runif函数的。从<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">100</span>中间选择。
<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[1]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10.90927</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[2]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">13.579156</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5.199927</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[3]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">74.93334</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">67.08987</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">91.84644</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[4]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">41.47904</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">90.65402</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">44.92566</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">79.38730</span>

#在lapply中书写匿名函数获取列表中每个矩阵的第一行。
> (x=list(a=matrix(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>),b=matrix(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>)))
$a
     [,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] [,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>] [,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>]
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,]    <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>    <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>    <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>,]    <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>    <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>    <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>

$b
     [,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] [,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>]
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,]    <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>    <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>,]    <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>    <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>

> lapply(x,<span class="hljs-function" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">function</span><span class="hljs-params" style="color: rgb(102, 0, 102); box-sizing: border-box;">(m)</span></span> m[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,])
$a
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>

$b
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li><li style="box-sizing: border-box; padding: 0px 5px;">61</li><li style="box-sizing: border-box; padding: 0px 5px;">62</li><li style="box-sizing: border-box; padding: 0px 5px;">63</li><li style="box-sizing: border-box; padding: 0px 5px;">64</li><li style="box-sizing: border-box; padding: 0px 5px;">65</li><li style="box-sizing: border-box; padding: 0px 5px;">66</li><li style="box-sizing: border-box; padding: 0px 5px;">67</li><li style="box-sizing: border-box; padding: 0px 5px;">68</li><li style="box-sizing: border-box; padding: 0px 5px;">69</li><li style="box-sizing: border-box; padding: 0px 5px;">70</li><li style="box-sizing: border-box; padding: 0px 5px;">71</li><li style="box-sizing: border-box; padding: 0px 5px;">72</li><li style="box-sizing: border-box; padding: 0px 5px;">73</li><li style="box-sizing: border-box; padding: 0px 5px;">74</li></ul>

3)、 sapply(列表,函数名/函数,其他参数)

sapply和lapply的差不多，但是sapply可以自动化简函数，

当结果列表长度为一的时候，返回向量。
当结果列表长度相同且大于一的时候返回矩阵。
当结果列表不等的时候仍然返回一个列表。

<code class="hljs ruby has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">> (x=list(a=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span><span class="hljs-symbol" style="color: rgb(0, 102, 102); box-sizing: border-box;">:</span><span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>,b=c(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">21</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">31</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">41</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">51</span>)))
<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">$a</span>
 [<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>

<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">$b</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">21</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">31</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">41</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">51</span>

> sapply(x,mean)  <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#返回结果变成了向量</span>
   a    b
 <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5.5</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">31.0</span>
> <span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">class</span>(<span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">sapply</span>(<span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">x</span>,<span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">mean</span>))</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"numeric"</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li></ul>

4)、 mapply(列表,函数名/函数,其他参数)

mapply(函数/函数名,数据,函数相关的参数) ，mapply是apply的多元版本。

<code class="hljs lua has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">> (u=list(rep(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>),rep(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>),rep(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>),rep(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)))
<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[1]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[2]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[3]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[4]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>

> (o=mapply(rep,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)) #<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>对应设置了前面的<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>重复次数，和上面的结果是一样的。
<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[1]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[2]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[3]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[4]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>

#自己写函数，再由mapply来调用
> s=<span class="hljs-function" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">function</span><span class="hljs-params" style="color: rgb(102, 0, 102); box-sizing: border-box;">(n,mean,std)</span></span>{
+   rnorm(n,mean,std) #从均值为mean，标准差为std的总体里抽取n个元素。
+ }
> s(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>) #测试函数
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.1789096</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.3389229</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.3318089</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.4226340</span>

#在mapply中调用自己写的函数，返回一个列表。
> mapply(s,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>) #<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>表示一次抽取<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>个元素，<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>表示对应前面五次每次的均值，<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>表示，这<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>次抽取的每个总体的标准差。
<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[1]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.89449</span>  #从均值为<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>标准差为<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>的整体中随机抽取<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>个

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[2]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.465339</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6.585427</span> #从均值为<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>标准差为<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>的整体中随机抽取<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>个

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[3]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.054207</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.269529</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5.044077</span> #从均值为<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>标准差为<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>的整体中随机抽取<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>个

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[4]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.6101787</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.7211071</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.6095973</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.4073418</span> #从均值为<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>标准差为<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>的整体中随机抽取<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>个

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[5]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.6578902</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.9364415</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.8377756</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.5111859</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.1535675</span> #从均值为<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>标准差为<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>的整体中随机抽取<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>个

list(s(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>),s(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>),s(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>),s(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>),s(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>)) #效果和上面用mapply是一样的。
<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[1]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.380181</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[2]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.345394</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.906018</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[3]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.7507204</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.8917604</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.4670050</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[4]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.589484</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.014790</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6.153610</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.452525</span>

<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">[[5]]</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.2042391</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.9790139</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.6326908</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.9025792</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.4117260</span>
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li><li style="box-sizing: border-box; padding: 0px 5px;">61</li><li style="box-sizing: border-box; padding: 0px 5px;">62</li><li style="box-sizing: border-box; padding: 0px 5px;">63</li><li style="box-sizing: border-box; padding: 0px 5px;">64</li><li style="box-sizing: border-box; padding: 0px 5px;">65</li><li style="box-sizing: border-box; padding: 0px 5px;">66</li></ul>

5)、 tapply(向量,因子/因子列表,函数/函数名)

对向量的子集进行操作

<code class="hljs autohotkey has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> > (x=c(rnorm(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>),runif(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>),rnorm(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)))
 [<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.1003527</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.6135971</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.9259782</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.6880730</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.1620147</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5222504</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.6076465</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.6647177</span>
 [<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span>]  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.3104704</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5861854</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.7122914</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.0757132</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.1427658</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.6782741</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.0646930</span>
> (f=gl(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>))
 [<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>
<span class="hljs-label" style="box-sizing: border-box;">Levels:</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>
> tapply(x,f,mean) #对x这个向量按照f的水平因子进行求均值的操作，<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>下面是x中前<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>个数的均值，<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>下面是x中间<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>个数的均值，<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>下面是x中后面<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>个数的均值。
>
         <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>          <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>          <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>
-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5276119</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5382541</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.3088703</span>
> tapply(x,f,mean,simplify=<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">FALSE</span>) #tapply函数中simplify的默认值是<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">TRUE</span>，完成了简化，否则返回的也是一个列表。
$<span class="hljs-escape" style="box-sizing: border-box;">`1</span><span class="hljs-escape" style="box-sizing: border-box;">`
</span>[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5276119</span>

$<span class="hljs-escape" style="box-sizing: border-box;">`2</span><span class="hljs-escape" style="box-sizing: border-box;">`
</span>[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5382541</span>

$<span class="hljs-escape" style="box-sizing: border-box;">`3</span><span class="hljs-escape" style="box-sizing: border-box;">`
</span>[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.30887</span>
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li></ul>

3、split

根据因子或者因子列表将向量或者其他对象进行分组操作
通常与lappy一起使用
spilt(向量/列表/数据框,因子/因子列表)

一般split函数是和lapply/sapply函数配合使用的，lapply(split(x,f),mean)，将x先按照f分组，再使用mean函数求均值，最后以列表的形式输出。

<code class="hljs autohotkey has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> > (x=c(rnorm(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>),runif(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>),rnorm(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)))
 [<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.1003527</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.6135971</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.9259782</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.6880730</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.1620147</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5222504</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.6076465</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.6647177</span>
 [<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span>]  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.3104704</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5861854</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.7122914</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.0757132</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.1427658</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.6782741</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.0646930</span>

> f
 [<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>
<span class="hljs-label" style="box-sizing: border-box;">Levels:</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>

> split(x,f)  #将x根据f分成相应的组
$<span class="hljs-escape" style="box-sizing: border-box;">`1</span><span class="hljs-escape" style="box-sizing: border-box;">`
</span>[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.1003527</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.6135971</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.9259782</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.6880730</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.1620147</span> #$<span class="hljs-escape" style="box-sizing: border-box;">`1</span><span class="hljs-escape" style="box-sizing: border-box;">`水</span>平<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>在x中对应的五个值

$<span class="hljs-escape" style="box-sizing: border-box;">`2</span><span class="hljs-escape" style="box-sizing: border-box;">`
</span>[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5222504</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.6076465</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.6647177</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.3104704</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5861854</span> #$<span class="hljs-escape" style="box-sizing: border-box;">`2</span><span class="hljs-escape" style="box-sizing: border-box;">`水</span>平<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>在x中对应的五个值

$<span class="hljs-escape" style="box-sizing: border-box;">`3</span><span class="hljs-escape" style="box-sizing: border-box;">`
</span>[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.712291</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.075713</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.142766</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.678274</span> -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.064693</span> #$<span class="hljs-escape" style="box-sizing: border-box;">`3</span><span class="hljs-escape" style="box-sizing: border-box;">`水</span>平<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>在x中对应的五个值

#将x先按照f分组，再使用mean函数求均值，最后以列表的形式输出。
> lapply(split(x,f),mean)
$<span class="hljs-escape" style="box-sizing: border-box;">`1</span><span class="hljs-escape" style="box-sizing: border-box;">`
</span>[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5276119</span>

$<span class="hljs-escape" style="box-sizing: border-box;">`2</span><span class="hljs-escape" style="box-sizing: border-box;">`
</span>[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5382541</span> 

$<span class="hljs-escape" style="box-sizing: border-box;">`3</span><span class="hljs-escape" style="box-sizing: border-box;">`
</span>[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.30887</span>

# colMeans是计算列的平均值的函数
> lapply(s,function(x) colMeans(x[,c(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Ozone"</span>,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Wind"</span>,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Temp"</span>)]))
$<span class="hljs-escape" style="box-sizing: border-box;">`5</span><span class="hljs-escape" style="box-sizing: border-box;">`
</span>   Ozone     Wind     Temp
      NA <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11.62258</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">65.54839</span> 

$<span class="hljs-escape" style="box-sizing: border-box;">`6</span><span class="hljs-escape" style="box-sizing: border-box;">`
</span>   Ozone     Wind     Temp
      NA <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10.26667</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">79.10000</span> 

$<span class="hljs-escape" style="box-sizing: border-box;">`7</span><span class="hljs-escape" style="box-sizing: border-box;">`
</span>    Ozone      Wind      Temp
       NA  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8.941935</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">83.903226</span> 

$<span class="hljs-escape" style="box-sizing: border-box;">`8</span><span class="hljs-escape" style="box-sizing: border-box;">`
</span>    Ozone      Wind      Temp
       NA  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8.793548</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">83.967742</span> 

$<span class="hljs-escape" style="box-sizing: border-box;">`9</span><span class="hljs-escape" style="box-sizing: border-box;">`
</span>Ozone  Wind  Temp
   NA <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10.18</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">76.90</span>
#所有Ozone的均值都是NA，说明是有确实存在，所以导致计算列均值的时候也是缺失值。

> sapply(s,function(x) colMeans(x[,c(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Ozone"</span>,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Wind"</span>,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Temp"</span>)],na.rm = <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">TRUE</span>))
             <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>        <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>         <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>         <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span>        <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span>
Ozone <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">23.61538</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">29.44444</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">59.115385</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">59.961538</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">31.44828</span>
Wind  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11.62258</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10.26667</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8.941935</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8.793548</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10.18000</span>
Temp  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">65.54839</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">79.10000</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">83.903226</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">83.967742</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">76.90000</span>
#设置sapply函数的na.rm属性为<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">TRUE</span>是可以忽略缺失值的。

#当然，比较<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>的做法是我们自己是我们自己手动清洗数据
> g=complete.cases(airquality) #第一步，调用complete.cases()清洗数据
> s_tmp=split(airquality[g,],airquality$Month) #第二步，调用split方法来将已经清洗过的数据根据月份来分组。
> sapply(s_tmp,function(x) colMeans(x[,c(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Ozone"</span>,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Wind"</span>,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Temp"</span>)])) #调用sapply方法并且自己写一个匿名函数来求特定域的均值。
             <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>         <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>         <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>        <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span>   <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span>
Ozone <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">26.41935</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">53.666667</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">59.258065</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">21.42105</span> NaN
Wind  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11.73871</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8.803333</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8.619355</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10.95263</span> NaN
Temp  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">69.35484</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">83.066667</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">84.161290</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">72.84211</span> NaN
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li><li style="box-sizing: border-box; padding: 0px 5px;">61</li><li style="box-sizing: border-box; padding: 0px 5px;">62</li><li style="box-sizing: border-box; padding: 0px 5px;">63</li><li style="box-sizing: border-box; padding: 0px 5px;">64</li><li style="box-sizing: border-box; padding: 0px 5px;">65</li><li style="box-sizing: border-box; padding: 0px 5px;">66</li><li style="box-sizing: border-box; padding: 0px 5px;">67</li><li style="box-sizing: border-box; padding: 0px 5px;">68</li></ul>

排序

sort：对向量进行排序，返回排好序的内容。
order：返回排序好的内容的下标/多个排序标准。

<code class="hljs php has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">> (x=data.frame(v1=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>,v2=c(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span>),v3=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">15</span>,v4=c(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)))
  v1 v2 v3 v4
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">12</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">13</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">14</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">15</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>
> (sort(x<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">$v2</span>)) <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#按升序排列</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>
> (sort(x<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">$v2</span>,decreasing=<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">TRUE</span>)) <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#按降序排列</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>
> order(x<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">$v2</span>) <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#order是返回下标的，不返回内容。</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>
> x[order(x<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">$v2</span>),] <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#调用得到的下标打印</span>
  v1 v2 v3 v4
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">14</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">12</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">15</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">13</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>
> x[order(x<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">$v4</span>,x<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">$v2</span>),]  <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#先按照v4进行排序，v4中有相同的再按照v2进行排序。</span>
  v1 v2 v3 v4
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">12</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">15</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">14</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">13</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>
> x[order(x<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">$v4</span>,x<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">$v2</span>,decreasing=<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">TRUE</span>),] <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#降序排列。</span>
  v1 v2 v3 v4
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">13</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">14</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">15</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>
<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">12</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li></ul>

数据处理流程

原始数据（raw dataset） —> 预处理后的数据（clean dataset）

构建子集 subsetting

1、构建方法

[] 提取一个或者多类型相同的元素 R语言中下标是从1开始的。
[[]] 从列表或者数据框中提取数据
$按照名字从列表或者数据框中提取元素

举例

1. 设置条件进行子集提取

<code class="hljs php has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">> (x=c(rnorm(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">20</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>)))
 [<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.63156732</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.76807795</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6.17118143</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.43515444</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.59313881</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.16966527</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.41943174</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.81982118</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.10841749</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11.16069947</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.09089112</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.62378612</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8.43299270</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5.97803844</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.64061372</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.85256809</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7.55771969</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7.94601703</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">19</span>]  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.93132473</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.63224266</span>

> x[x><span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>] <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#设置条件进行子集提取</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6.171181</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11.160699</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8.432993</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5.978038</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7.557720</span>  <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7.946017</span>

> x><span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#直接输入x>5可以得到对向量中每个元素的大小的判断</span>
 [<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">FALSE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">FALSE</span>  <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">TRUE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">FALSE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">FALSE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">FALSE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">FALSE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">FALSE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">FALSE</span>  <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">TRUE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">FALSE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">FALSE</span>  <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">TRUE</span>  <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">TRUE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">FALSE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">FALSE</span>  <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">TRUE</span>  <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">TRUE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">FALSE</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">20</span>] <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">FALSE</span>

> (y=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>)
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>
> y[y<=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>|y>=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>]
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>
> y[-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>]  <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">#加负号代表将数据去除</span>
[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>] <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span></code>

时间： 2024-09-30 20:53:20

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