The “mutate_all” Function in R

• Package: dplyr

• Purpose: To apply a transformation to all columns in a data frame and create new columns with the results.

• General Class: Data Manipulation

• Required Argument(s):

• data: The data frame to mutate.

• list(): A list of functions to apply to each column.

• 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)
  )
  
  # Create a multiplication function
  Mult_by_2 <- function(x,y=2){return(x*y)}
  
  # Mutate all columns by doubling their values
  mutated_data <- data %>%
  mutate_all(list(Mult = Mult_by_2))
  
  # Display the mutated data,
  # In this situation "mutate_at" would be better.
  print(mutated_data)

• In this example, the mutate_all function from the dplyr package is used to apply a transformation to all columns in the sample data frame data. The Mult_by_2 function doubles the values in each column. The result, mutated_data, contains the original columns along with new columns where the values are doubled.