R语言 sample_n()用法及代码示例

sample_n()R语言中的函数用于从 DataFrame 中随机抽取样本。

用法： sample_n(x, n)

参数：
x:数据帧
n:要选择的项目的大小/数量

范例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

范例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

这里，在上面的代码中，指定了列名。因此，在因子内应用了大小。

相关用法

注：本文由纯净天空筛选整理自nidhi_biet大神的英文原创作品 Take Random Samples from a Data Frame in R Programming – sample_n() Function。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。