Table of Contents
In R, you can subset a Data Frame by a list of values by using the subset function with the argument ‘in’. This argument takes a vector of values to use as a filter for the Data Frame. The function will then return a Data Frame with only those rows that contain one of the values in the list of values that was used to subset the original Data Frame.
You can use one of the following methods to subset a data frame by a list of values in R:
Method 1: Use Base R
df_new <- df[df$my_column %in% vals,] Method 2: Use dplyr
library(dplyr)
df_new <- filter(df, my_column %in% vals)
Method 3: Use data.table
library(data.table)
df_new <- setDT(df, key='my_column')[J(vals)]
The following examples show how to use each of these methods in practice with the following data frame in R:
#create data frame
df <- data.frame(team=c('A', 'B', 'B', 'B', 'C', 'C', 'C', 'D'),
points=c(12, 22, 35, 34, 20, 28, 30, 18),
assists=c(4, 10, 11, 12, 12, 8, 6, 10))
#view data frame
df
team points assists
1 A 12 4
2 B 22 10
3 B 35 11
4 B 34 12
5 C 20 12
6 C 28 8
7 C 30 6
8 D 18 10
Method 1: Subset Data Frame by List of Values in Base R
The following code shows how to subset the data frame to only contain rows that have a value of ‘A’ or ‘C’ in the team column:
#define values to subset by vals <- c('A', 'C') #subset data frame to only contain rows where team is 'A' or 'C' df_new <- df[df$team %in% vals,] #view results df_new team points assists 1 A 12 4 5 C 20 12 6 C 28 8 7 C 30 6
The resulting data frame only contains rows that have a value of ‘A’ or ‘C’ in the team column.
Note that we used functions from base R in this example so we didn’t have to load any extra packages.
Method 2: Subset Data Frame by List of Values in dplyr
The following code shows how to subset the data frame to only contain rows that have a value of ‘A’ or ‘C’ in the team column by using the filter() function from the dplyr package:
library(dplyr) #define values to subset by vals <- c('A', 'C') #subset data frame to only contain rows where team is 'A' or 'C' df_new <- filter(df, team %in% vals) #view results df_new team points assists 1 A 12 4 5 C 20 12 6 C 28 8 7 C 30 6
Method 3: Subset Data Frame by List of Values in data.table
The following code shows how to subset the data frame to only contain rows that have a value of ‘A’ or ‘C’ in the team column by using functions from the data.table package:
library(data.table) #define values to subset by vals <- c('A', 'C') #subset data frame to only contain rows where team is 'A' or 'C' df_new <- setDT(df, key='team')[J(vals)] #view results df_new team points assists 1: A 12 4 2: C 20 12 3: C 28 8 4: C 30 6
The resulting data frame only contains rows that have a value of ‘A’ or ‘C’ in the team column.
Related:
The following tutorials explain how to perform other common tasks in R: