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R语言for循环

程序员文章站 2024-02-03 11:17:22
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基本语法:for (name in expr_1) expr_2

实例操作:

1.构造矩阵

x=array(0,dim=c(4,4)) # 构造四阶矩阵 数值全为0
for (i in 1:4){
    for (j in 1:4){
        x[i,j]=1/(i+j+1)
  }
    }
print(x)
         [,1]      [,2]      [,3]      [,4]
[1,] 0.3333333 0.2500000 0.2000000 0.1666667
[2,] 0.2500000 0.2000000 0.1666667 0.1428571
[3,] 0.2000000 0.1666667 0.1428571 0.1250000
[4,] 0.1666667 0.1428571 0.1250000 0.1111111

2.利用循序进行单位根检验

nrow=20
ncol=5
A=matrix(nrow=nrow,ncol=ncol,data=NA)
for (i in 1:ncol) { A[,i]= rnorm(20, mean=0, sd=1) #构造正太分布,产生20个随机数,服从正太分布 }
library(tseries) #导入所需要的函数包 for (i in 1:5) {print(adf.test(A[,i]))} #AD

 结果如下,很方便.

Augmented Dickey-Fuller Test data: A[, i] Dickey-Fuller = -2.4773, Lag order = 2, p-value = 0.3905 alternative hypothesis: stationary Augmented Dickey-Fuller Test data: A[, i] Dickey-Fuller = -1.8836, Lag order = 2, p-value = 0.6167 alternative hypothesis: stationary Augmented Dickey-Fuller Test data: A[, i] Dickey-Fuller = -3.5647, Lag order = 2, p-value = 0.05491 alternative hypothesis: stationary Augmented Dickey-Fuller Test data: A[, i] Dickey-Fuller = -2.2957, Lag order = 2, p-value = 0.4597 alternative hypothesis: stationary Augmented Dickey-Fuller Test data: A[, i] Dickey-Fuller = -2.2784, Lag order = 2, p-value = 0.4663 alternative hypothesis: stationary

  

F单位根检验