The “coalesce” Function in R

• Package: dplyr

• Purpose: To return the first non-missing value from a set of vectors.

• General Class: Data Manipulation

• Required Argument(s):

• ...: Vectors or column names to evaluate.

• 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, 4, 5),
  value1 = c(NA, 15, NA, 25, NA),
  value2 = c(10, NA, 20, NA, 30)
  )
  
  # Create a new column 'filled_value' with the first non-missing value from 'value1' and 'value2'
  result <- data %>%
  mutate(filled_value = coalesce(value1, value2))
  
  # Display the result
  print(result)

• In this example, the coalesce function from the dplyr package is used to create a new column ‘filled_value’ in the sample data frame data. The ‘filled_value’ column is assigned the first non-missing value from the ‘value1’ and ‘value2’ columns for each row. If both ‘value1’ and ‘value2’ are missing for a row, the ‘filled_value’ will also be missing. The result is a new data frame result containing the original data along with the newly created ‘filled_value’ column.