How to Filter For Unique Values Using dplyr?

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You can use the following methods to filter for unique values in a data frame in R using the package:

Method 1: Filter for Unique Values in One Column

df %>% distinct(var1)

Method 2: Filter for Unique Values in Multiple Columns

df %>% distinct(var1, var2)

Method 3: Filter for Unique Values in All Columns

df %>% distinct()

The following examples show how to use each method in practice with the following data frame in R:

#create data frame
df <- data.frame(team=c('A', 'A', 'A', 'A', 'B', 'B', 'B', 'B'),
                 points=c(10, 10, 8, 6, 15, 15, 12, 12),
                 rebounds=c(8, 8, 4, 3, 10, 11, 7, 7))

#view data frame
df

  team points rebounds
1    A     10        8
2    A     10        8
3    A      8        4
4    A      6        3
5    B     15       10
6    B     15       11
7    B     12        7
8    B     12        7

Example 1: Filter for Unique Values in Column

We can use the following code to filter for unique values in just the team column:

library(dplyr)

#select only unique values in team column
df %>% distinct(team)

  team
1    A
2    B

Notice that only the unique values in the team column are returned.

Example 2: Filter for Unique Values in Multiple Columns

We can use the following code to filter for unique values in the team and points columns:

library(dplyr)

#select unique values in team and points columns
df %>% distinct(team, points)

  team points
1    A     10
2    A      8
3    A      6
4    B     15
5    B     12

Notice that only the unique values in the team and points columns are returned.

Example 3: Filter for Unique Values in All Columns

We can use the following code to filter for unique values across all columns in the data frame:

library(dplyr)

#select unique values across all columns
df %>% distinct()

  team points rebounds
1    A     10        8
2    A      8        4
3    A      6        3
4    B     15       10
5    B     15       11
6    B     12        7

Notice that the unique values across all three columns are returned.

Note: You can find the complete documentation for the distinct function in dplyr .

The following tutorials explain how to perform other common operations in dplyr: