The select() function in R is used to select columns of a data frame that you want to focus on. It can be used to select columns by name, by index, and also is used to rename variables while selecting, and dropping variables by name.
The select() function has a number of features that make it a powerful tool for data analysis. For example, you can use the select() function to:
- Select a range of columns by name.
- Select columns by their index.
- Select columns that match a pattern.
- Rename columns while selecting them.
- Drop columns from a data frame.
The select() function is a key part of the dplyr package, which is a collection of data manipulation functions for R. The dplyr package is a popular choice for data analysis because it provides a concise and intuitive syntax for working with data frames.
Examples of how to use the select() function
# Select the first three columns of a data frame
select(chicago, city:dptp)
# Select all columns except the first three columns
select(chicago, -(city:dptp))
# Select all columns that end with a "2"
select(chicago, ends_with("2"))
# Select all columns that start with a "d"
select(chicago, starts_with("d"))
# Rename the "dptp" column to "pressure"
select(chicago, city, tmpd, pressure = dptp)
# Drop the "city" column
select(chicago, -city)
