R语言 从数据框中获取随机样本 – sample_n()函数

R语言中的 sample_n() 函数用于从数据框中抽取随机样本。

语法： sample_n(x, n)

参数：

x： 数据框

n： 要选择的项目的大小/数量

例子1 :

# R program to collect sample data
# from a data frame
  
# Loading library 
library(dplyr)
    
# Create a data frame
d <- data.frame( name = c("Abhi", "Bhavesh", "Chaman", "Dimri"),  
                 age = c(7, 5, 9, 16),  
                 ht = c(46, NA, NA, 69), 
                 school = c("yes", "yes", "no", "no") ) 
  
# Printing three rows 
sample_n(d, 3) 

输出

     name age ht school
1  Chaman   9 NA     no
2    Abhi   7 46    yes
3 Bhavesh   5 NA    yes

例2 :

# R program to collect sample data
# from a data frame
  
# Loading library 
library(dplyr)
    
# Create a data frame
d <- data.frame( name = c("Abhi", "Bhavesh", "Chaman", "Dimri"),  
                 age = c(7, 5, 9, 16),  
                 ht = c(46, NA, NA, 69), 
                 school = c("yes", "yes", "no", "no") ) 
  
# Printing three rows 
sample_n(d, 3, fac = "name")$name

输出

[1] Chaman  Bhavesh Dimri  
Levels: Abhi Bhavesh Chaman Dimri

在这里，在上述代码中，列名被指定。因此，尺寸被应用在因子内。