stby: Obtain Grouped Statistics With summarytools

In dcomtois/summarytools: Tools to Quickly and Neatly Summarize Data

Obtain Grouped Statistics With summarytools

Description

An adaptation base R's by function, designed to optimize the results' display.

Usage

stby(data, INDICES, FUN, ..., useNA = FALSE)

Arguments

data	an R object, normally a data frame, possibly a matrix.
INDICES	a grouping variable or a list of grouping variables, each of length nrow(data).
FUN	a function to be applied to (usually data-frame) subsets of data.
...	Further arguments to FUN.
useNA	Make NA a valid grouping value in INDICES variable(s). Set to FALSE explicitly to eliminate message.

Details

When the grouping variable(s) contain NA values, the base::by function (as well as summarytools versions prior to 1.1.0) ignores corresponding groups. Version 1.1.0 allows setting useNA = TRUE to make new groups using NA values on the grouping variable(s), just as dplyr::group_by does.

When NA values are detected and useNA = FALSE, a message is displayed; to disable this message, set check.nas = FALSE.

Value

An object of classes “list” and “summarytools”, giving results for each subset.

See Also

by, group_by

Examples

data("tobacco")
with(tobacco, stby(data = BMI, INDICES = gender, FUN = descr,
                   check.nas = FALSE))
with(tobacco, stby(data = smoker, INDICES = gender, freq, useNA = TRUE))
with(tobacco, stby(data = list(x = smoker, y = diseased),
                   INDICES = gender, FUN = ctable, useNA = TRUE))
                   

dcomtois/summarytools documentation built on March 1, 2025, 8:50 p.m.