Often you may want to “clean” the column names of a data frame in R so that they all have a standard pattern or case.
One of the best ways to do so is by using the clean_names() function from the janitor package in R, which can be used to perform this exact task.
The clean_names() function uses the following syntax:
clean_names(dat, case)
where:
- dat: Name of data frame
- case: The desired target case
Note that the case argument can take on any of the following values:
- “snake” produces snake_case
- “lower_camel” produces lowerCamel”
- “upper_camel” produces UpperCamel
- “all_caps” produces ALL_CAPS
- “lower_upper” produces lowerUPPER
- “upper_lower” produces UPPERlower
Typically you will use this function when you’re in the data cleaning phase of a project and you would like all of the columns in a particular data frame to have a uniform pattern.
The following example shows how to use the clean_names() function in practice in R.
Note: Before using the clean_names() function, you may need to first install the janitor package. You can use the following syntax to do so:
install.packages('janitor')
Once the janitor package has been installed, you can proceed to use the clean_names() function.
Example: How to Use the clean_names() Function in R
Suppose that we create a data frame in R that contains information about various basketball players:
#create data frame
df <- data.frame(TEAM=c('A', 'A', 'A', 'A', 'B', 'B', 'B', 'B'),
pointsscored=c(99, 68, 86, 88, 95, 74, 78, 93),
assists=c(22, 28, 31, 35, 34, 45, 28, 31),
Totalrebounds=c(30, 28, 24, 24, 30, 36, 30, 29))
#view data frame
df
TEAM pointsscored assists Totalrebounds
1 A 99 22 30
2 A 68 28 28
3 A 86 31 24
4 A 88 35 24
5 B 95 34 30
6 B 74 45 36
7 B 78 28 30
8 B 93 31 29
Notice that the column names seem to have no consistency in the pattern or style in which they are named.
To “clean” up the names and give them all a uniform style, we can use the clean_names() function from the janitor package.
We can use the following syntax to do so:
library(janitor)
#clean names of data frame
clean_names(df)
team pointsscored assists totalrebounds
1 A 99 22 30
2 A 68 28 28
3 A 86 31 24
4 A 88 35 24
5 B 95 34 30
6 B 74 45 36
7 B 78 28 30
8 B 93 31 29
This returns the exact same data frame with the column names “cleaned” so that they all have the same case.
Note that we can use the case argument to specify a specific case to use if we’d like.
For example, we can use the following syntax to convert each column name to only uppercase characters:
library(janitor)
#clean names of data frame
clean_names(df, case='all_caps')
TEAM POINTSSCORED ASSISTS TOTALREBOUNDS
1 A 99 22 30
2 A 68 28 28
3 A 86 31 24
4 A 88 35 24
5 B 95 34 30
6 B 74 45 36
7 B 78 28 30
8 B 93 31 29
This returns the same data frame with all column names converted to uppercase characters.
We could also choose a different case to use, such as lower_camel, which converts each column name to a lower camel case:
library(janitor)
#clean names of data frame
clean_names(df, case='lower_camel')
team pointsscored assists totalrebounds
1 A 99 22 30
2 A 68 28 28
3 A 86 31 24
4 A 88 35 24
5 B 95 34 30
6 B 74 45 36
7 B 78 28 30
8 B 93 31 29
Each column name now has a lower camel case.
Feel free to use whichever case you would like by specifying it in the case argument of the clean_names() function.
Additional Resources
The following tutorials explain how to perform other common tasks in R:
How to Sort a Table in R
How to Plot a Table in R
How to Create a Three-Way Table in R
How to Create a Frequency Table by Group in R
