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