groupStatI: Perform Summary Analysis by Group Using an column Index
Description
This function applies a specified function to each group defined by an column index,
and returns a summary of the results. It is useful for summarizing data by
group when the groups are defined by an column index.
Usage
groupStatI(f, x, idx)
Value
A list containing the summary statistics for each group.
Arguments
f
A function that takes a single argument and returns a summary of the data.
x
A data frame or matrix containing the data to be summarized.
idx
A list of indices or group names that define the column groups.