The “select_if” Function in R

• Package: dplyr

• Purpose: To select columns in a data frame based on specified conditions applied to each column.

• General Class: Data Manipulation

• Required Argument(s):

• data: The data frame to select columns from.

• predicate: A function or formula specifying the conditions for column selection.

• Notable Optional Arguments:

• None.

• Example (with Explanation):

• # Load necessary packages
  library(dplyr)
  
  # Create a sample data frame
  data <- data.frame(
  ID = c(1, 2, 3),
  value1 = c(10, 15, 20),
  value2 = c(25, 30, 35),
  category = c("A", "B", "A")
  )
  
  # Select columns where all values are numeric
  selected_columns <- data %>%
  select_if(is.numeric)
  
  # Display the selected columns
  print(selected_columns)

• In this example, the select_if function from the dplyr package is used to select columns from the sample data frame data where all values are numeric. The is.numeric predicate function is applied to each column, and only the numeric columns are retained in the selected_columns result.