eda_shuffle: Shuffle values across groups

In mgimond/tukeyedar: Tukey Inspired Exploratory Data Analysis Functions

Shuffle values across groups

Description

This function shuffles the values in a specified column of a data frame across all groups.

Usage

eda_shuffle(df, x, grp, replace_x = FALSE, replace_grp = FALSE, ...)

Arguments

df	A data frame.
x	The name of the column containing the values to be shuffled.
grp	The name of the column containing the grouping factor.
replace_x	A logical value indicating whether to sample values with replacement (default: FALSE).
replace_grp	A logical value indicating whether to preserve the factor levels of the grouping column (default: TRUE).
...	Not used

Details

Shuffling/permuting values across groups has, for effect, sampling from a same distribution within each group level. This simulates a process where differences between group levels are solely a function of random noise.

By default, the group distribution does not change. If you wish to allow the group distribution to change (i.e. having a different number of group levels), set replace_grp = TRUE. But, note that for small datasets, this may result in empty group levels.

Value

A data frame with the shuffled values and the original group assignments. The column names of the output data frame will match the input column names.

Examples

# Original data
eda_boxls(mtcars, hp, cyl, reorder = FALSE)

# Permute values across cyl groups
df1 <- eda_shuffle(mtcars, hp, cyl)
eda_boxls(df1, hp, cyl)

# Is the variability explained by cyl due to chance alone or is it
# systematic?
OP <- par(mfrow = c(2,2))
 eda_boxls(mtcars, hp, cyl, reorder = FALSE)
 title("Original", col.main = "darkred")
 eda_boxls(eda_shuffle(mtcars, hp, cyl), hp, cyl, reorder = FALSE)
 eda_boxls(eda_shuffle(mtcars, hp, cyl), hp, cyl, reorder = FALSE)
 eda_boxls(eda_shuffle(mtcars, hp, cyl), hp, cyl, reorder = FALSE)
par(OP)

mgimond/tukeyedar documentation built on Feb. 1, 2025, 4:02 a.m.