R語言 filter()用法及代碼示例

filter()R語言中的函數用於選擇案例並根據過濾表達式過濾掉值。

用法： filter(x, expr)

參數：
x:要過濾的對象
expr:作為過濾基礎的表達式

範例1：


# R Program to filter cases
  
# Loading library
library(dplyr)
  
# Create a data frame with missing data  
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") ) 
d 
    
# Finding rows with NA value 
filter(d, is.na(ht)) 
    
# Finding rows with no NA value 
filter(d, ! is.na(ht))

輸出：

     name age ht school
1    Abhi   7 46    yes
2 Bhavesh   5 NA    yes
3  Chaman   9 NA     no
4   Dimri  16 69     no
     name age ht school
1 Bhavesh   5 NA    yes
2  Chaman   9 NA     no
   name age ht school
1  Abhi   7 46    yes
2 Dimri  16 69     no

範例2：


# R Program to filter cases
  
# 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", "no", "yes", "no") ) 
d 
    
# Finding rows with school
filter(d, school == "yes") 
    
# Finding rows with no school
filter(d, school == "no")

輸出：

     name age ht school
1    Abhi   7 46    yes
2 Bhavesh   5 NA     no
3  Chaman   9 NA    yes
4   Dimri  16 69     no
    name age ht school
1   Abhi   7 46    yes
2 Chaman   9 NA    yes
     name age ht school
1 Bhavesh   5 NA     no
2   Dimri  16 69     no

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 Filter Out the Cases from an Object in R Programming – filter() 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。