caret: downSample – R documentation

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downSample

Down- and Up-Sampling Imbalanced Data

Description

downSample will randomly sample a data set so that all classes have the same frequency as the minority class. upSample samples with replacement to make the class distributions equal

Usage

downSample(x, y, list = FALSE, yname = "Class")

Arguments

`x`	a matrix or data frame of predictor variables
`y`	a factor variable with the class memberships
`list`	should the function return `list(x, y)` or bind `x` and `y` together? If `FALSE`, the output will be coerced to a data frame.
`yname`	if `list = FALSE`, a label for the class column

Details

Simple random sampling is used to down-sample for the majority class(es). Note that the minority class data are left intact and that the samples will be re-ordered in the down-sampled version.

For up-sampling, all the original data are left intact and additional samples are added to the minority classes with replacement.

Value

Either a data frame or a list with elements x and y.

Author(s)

Max Kuhn

Examples

## A ridiculous example...
data(oil)
table(oilType)
downSample(fattyAcids, oilType)

upSample(fattyAcids, oilType)

caret

Classification and Regression Training

v6.0-86

GPL (>= 2)

Authors

Max Kuhn [aut, cre], Jed Wing [ctb], Steve Weston [ctb], Andre Williams [ctb], Chris Keefer [ctb], Allan Engelhardt [ctb], Tony Cooper [ctb], Zachary Mayer [ctb], Brenton Kenkel [ctb], R Core Team [ctb], Michael Benesty [ctb], Reynald Lescarbeau [ctb], Andrew Ziem [ctb], Luca Scrucca [ctb], Yuan Tang [ctb], Can Candan [ctb], Tyler Hunt [ctb]

Initial release