The “aggregate” Function in R

• Package: Base R (no specific package required)

• Purpose: Applies a function to the data in each group of a data frame.

• General Class: Data Manipulation

• Required Argument(s):

• x: A data frame or matrix.

• by: A list of grouping elements, typically the grouping variables.

• Notable Optional Arguments:

• FUN: The function to be applied to each group. It can be a function or a formula.

• ...: Additional arguments to pass to the function specified by FUN.

• simplify: A logical value indicating whether to simplify the result.

• Example:

• # Example data for aggregating using the aggregate function
  df <- data.frame(
  ID = c(1, 2, 3, 4, 5, 6),
  Category = c("A", "B", "A", "B", "A", "B"),
  Value = c(10, 15, 20, 25, 30, 35)
  )
  
  # Aggregate the sum of "Value" by "Category"
  aggregated_df <- aggregate(Value ~ Category, data = df, FUN = sum)
  
  # Display the aggregated data frame
  print(aggregated_df)

• In this example, the aggregate function from base R is used to aggregate the sum of the “Value” column by the “Category” column in a data frame (df). The result is an aggregated data frame (aggregated_df).