R中的外部（）函数

R编程语言中的outer()函数 用于将函数应用于两个数组。

Syntax: outer(x, y, FUN=”*”, …)

Parameters:

x, y: arrays
FUN: function to use on the outer products, default value is multiply

R 编程示例中的 outer()函数

示例 1：两个向量的外积

R

# R program to illustrate
# outer function
  
# Initializing two arrays of elements
x <- c(1, 2, 3, 4, 5)
y<- c(2, 4, 6)
  
# Multiplying array x elements with array y elements
# Here multiply (*) parameter is not used still this 
# function take it as default
outer(x, y)

R

# R program to illustrate
# outer function
  
# Initializing two arrays of elements
x <- 1:8
y<- 4
  
# Multiplying array x elements with array y elements
# Here multiply (*) parameter is not used still this 
# function take it as default
outer(x, y, "+")

输出：

[, 1] [, 2] [, 3]
[1, ]    2    4    6
[2, ]    4    8   12
[3, ]    6   12   18
[4, ]    8   16   24
[5, ]   10   20   30

示例 2：向量和单值的外部函数

R

# R program to illustrate
# outer function
  
# Initializing two arrays of elements
x <- 1:8
y<- 4
  
# Multiplying array x elements with array y elements
# Here multiply (*) parameter is not used still this 
# function take it as default
outer(x, y, "+")

输出：

[,1]
[1,]    5
[2,]    6
[3,]    7
[4,]    8
[5,]    9
[6,]   10
[7,]   11
[8,]   12