You can use the following basic syntax with the select_if() function from the dplyr package to select columns in a data frame that meet one of several conditions:
df %>% select_if(function(x) condition1 | condition2)
The following examples show how to use this syntax in practice.
Example 1: Use select_if() with Class Types
The following code shows how to use the select_if() function to select the columns in a data frame that have a class type of character or numeric:
library(dplyr) #create data frame df frame(team=c('A', 'B', 'C', 'D', 'E'), conference=as.factor(c('W', 'W', 'W', 'E', 'E')), points_for=c(99, 90, 86, 88, 95), points_against=c(91, 80, 88, 86, 93)) #select all character and numeric columns df %>% select_if(function(x) is.character(x) | is.numeric(x)) team points_for points_against 1 A 99 91 2 B 90 80 3 C 86 88 4 D 88 86 5 E 95 93
Notice that the one character column (team) and the two numeric columns (points_for and points_against) are returned while the factor column (conference) is not returned.
Example 2: Use select_if() with Class Types and Column Names
The following code shows how to use the select_if() function to select the columns in a data frame that have a class type of factor or have a column name of points_for:
library(dplyr) #create data frame df frame(team=c('A', 'B', 'C', 'D', 'E'), conference=as.factor(c('W', 'W', 'W', 'E', 'E')), points_for=c(99, 90, 86, 88, 95), points_against=c(91, 80, 88, 86, 93)) #select all factor columns and 'points_for' column df %>% select_if(function(x) is.factor(x) | all(x == .$points_for)) conference points_for 1 W 99 2 W 90 3 W 86 4 E 88 5 E 95
Notice that the one factor column and the one column titled points_for are returned.
Note: The | symbol is the “OR” logical operator in R. Feel free to use as many | symbols as you’d like to select columns using more than two conditions.
Additional Resources
The following tutorials explain how to use other common functions in dplyr:
How to Use the across() Function in dplyr
How to Use the relocate() Function in dplyr
How to Use the slice() Function in dplyr