downSample
Down- and Up-Sampling Imbalanced Data
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
- Keywords
- utilities
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 bindxandytogether? IfFALSE, 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.
Examples
# NOT RUN {
## A ridiculous example...
data(oil)
table(oilType)
downSample(fattyAcids, oilType)
upSample(fattyAcids, oilType)
# }