Select column which contains a value or matches a pattern

Select column(s) by position

Select column which starts with or ends with certain character

Here, we will display the column values based on values or pattern present in the column

Method 1: Using contains()

Display the column that contains the given sub string

Syntax:

select(dataframe,contains(‘sub_string’))

Here, dataframe is the input dataframe and sub_string is the string present in the column name

Example: R program to select column based on substring

R

# load the library 
library(dplyr) 
  
# create dataframe with 3 columns  
# id,name and address 
data1=data.frame(id=c(1,2,3,4,5,6,7,1,4,2), 
                   
                 name=c('sravan','ojaswi','bobby','gnanesh', 
                        'rohith','pinkey','dhanush','sravan', 
                        'gnanesh','ojaswi'), 
                   
                 address=c('hyd','hyd','ponnur','tenali', 
                           'vijayawada','vijayawada','guntur', 
                           'hyd','tenali','hyd')) 
  
# select column that contains am 
print(select(data1,contains('am'))) 
  
# select column that contains d 
print(select(data1,contains('d'))) 
  
# select column that contains dd 
print(select(data1,contains('dd')))

Output:

Method 2: Using matches()

It will check and display the column that contains the given sub string

select(dataframe,matches(‘sub_string’))

Here, dataframe is the input dataframe and sub_string is the string present in the column name

Example: R program to select column based on substring

R

# load the library 
library(dplyr) 
  
# create dataframe with 3 columns  
# id,name and address 
data1=data.frame(id=c(1,2,3,4,5,6,7,1,4,2), 
                   
                 name=c('sravan','ojaswi','bobby','gnanesh', 
                        'rohith','pinkey','dhanush','sravan', 
                        'gnanesh','ojaswi'), 
                   
                 address=c('hyd','hyd','ponnur','tenali', 
                           'vijayawada','vijayawada','guntur', 
                           'hyd','tenali','hyd')) 
  
# select column that matches with  am 
print(select(data1,matches('am'))) 
  
# select column that matches with d 
print(select(data1,matches ('d'))) 
  
# select column that matches with  dd 
print(select(data1,matches ('dd')))

Output:

Select variables (columns) in R using Dplyr

In this article, we are going to select variables or columns in R programming language using dplyr library.

Dataset in use:

Tags:

#R Dplyr #R Language