R語言 sample_n()用法及代碼示例

sample_n()R語言中的函數用於從 DataFrame 中隨機抽取樣本。

用法： sample_n(x, n)

參數：
x:數據幀
n:要選擇的項目的大小/數量

範例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)

輸出：

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

範例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

輸出：

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

這裏，在上麵的代碼中，指定了列名。因此，在因子內應用了大小。

相關用法

注：本文由純淨天空篩選整理自nidhi_biet大神的英文原創作品 Take Random Samples from a Data Frame in R Programming – sample_n() Function。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。