R语言 计算矩阵的交叉乘积 – crossprod()函数

R语言中的 crossprod() 函数用于返回指定矩阵的交叉乘积。

语法： crossprod(x)

参数：

x： 数字矩阵

例1 :

# R program to illustrate
# crossprod function
  
# Initializing a matrix with
# 2 rows and 2 columns
x <- matrix(1:4, 2, 2)
  
# Getting the matrix representation
x
  
# Calling the crossprod() function
crossprod(x)

输出

     [, 1] [, 2]
[1, ]    1    3
[2, ]    2    4

     [, 1] [, 2]
[1, ]    5   11
[2, ]   11   25

例2 :

# R program to illustrate
# crossprod function
  
# Initializing a matrix with
# 3 rows and 3 columns
x <- matrix(1:9, 3, 3)
  
# Getting the matrix representation
x
  
# Calling the crossprod() function
crossprod(x)

输出

     [, 1] [, 2] [, 3]
[1, ]    1    4    7
[2, ]    2    5    8
[3, ]    3    6    9

     [, 1] [, 2] [, 3]
[1, ]   14   32   50
[2, ]   32   77  122
[3, ]   50  122  194