R语言 构建对角线矩阵 – diag()函数

R语言中的 diag() 函数用于构造一个对角线矩阵。

语法： diag(x, nrow, ncol)

参数：

x： 作为对角线元素的值。

nrow, ncol： 代表元素的行和列的数量。

例1：

# R program to illustrate
# diag function
 
# Calling the diag() function with
# some number which will act as
# rows as well as columns number
diag(3)
diag(5)

输出：

     [, 1] [, 2] [, 3]
[1, ]    1    0    0
[2, ]    0    1    0
[3, ]    0    0    1

     [, 1] [, 2] [, 3] [, 4] [, 5]
[1, ]    1    0    0    0    0
[2, ]    0    1    0    0    0
[3, ]    0    0    1    0    0
[4, ]    0    0    0    1    0
[5, ]    0    0    0    0    1

例2：

# R program to illustrate
# diag function
 
# Calling the diag() function
diag(5, 2, 3)
diag(10, 3, 3)

输出：

     [, 1] [, 2] [, 3]
[1, ]    5    0    0
[2, ]    0    5    0

     [, 1] [, 2] [, 3]
[1, ]   10    0    0
[2, ]    0   10    0
[3, ]    0    0   10