在 R 编程中将数据帧转换为数值矩阵 – data.matrix()函数

R 语言中的data.matrix()函数用于通过将 Data Frame 的所有值转换为数字模式，然后将它们绑定为矩阵来创建矩阵。

Syntax: data.matrix(df)

Parameters:
df: Data frame to be converted.

示例 1：

# R program to convert a data frame
# into a numeric matrix
    
# Creating a dataframe 
df1 = data.frame( 
  "Name" = c("Amar", "Akbar", "Ronald"), 
  "Language" = c("R", "Python", "C#"), 
  "Age" = c(26, 38, 22) 
) 
  
# Printing data frame
print(df1)
  
# Converting into numeric matrix
df2 <- data.matrix(df1)
df2

输出：

Name Language Age
1   Amar        R  26
2  Akbar   Python  38
3 Ronald       C#  22
     Name Language Age
[1, ]    2        3  26
[2, ]    1        2  38
[3, ]    3        1  22

示例 2：

# R program to convert a data frame
# into a numeric matrix
    
# Creating a dataframe 
df <- data.frame(sample(LETTERS[1:4], 8, 
                 replace = T), cbind(1:4, 1:8))
colnames(df) <- c("x", "y", "z")
  
# Printing data frame
print(df)
  
# Converting into numeric matrix
df2 <- data.matrix(df)
df2

输出：

x y z
1 A 1 1
2 D 2 2
3 C 3 3
4 A 4 4
5 B 1 5
6 B 2 6
7 A 3 7
8 C 4 8
     x y z
[1, ] 1 1 1
[2, ] 4 2 2
[3, ] 3 3 3
[4, ] 1 4 4
[5, ] 2 1 5
[6, ] 2 2 6
[7, ] 1 3 7
[8, ] 3 4 8