Winsorize {DescTools}R Documentation

Winsorize (Replace Extreme Values by Less Extreme Ones)

Description

Winsorizing a vector means that a predefined quantum of the smallest and/or the largest values are replaced by less extreme values. Thereby the substitute values are the most extreme retained values.

Usage

Winsorize(x, minval = NULL, maxval = NULL, probs = c(0.05, 0.95),
          na.rm = FALSE)

Arguments

x

a numeric vector to be winsorized.

minval

the low border, all values being lower than this will be replaced by this value. The default is set to the 5%-quantile of x.

maxval

the high border, all values being larger than this will be replaced by this value. The default is set to the 95%-quantile of x.

probs

numeric vector of probabilities with values in [0,1] as used in quantile.

na.rm

should NAs be omitted to calculate the quantiles?
Note that NAs in x are preserved and left unchanged anyway.

Details

The winsorized vector is obtained by

wins(x) = -c if x < -c, c if x > c, x otherwise

Consider standardizing (possibly robust) the data before winsorizing.

Value

A vector of the same length as the original data x containing the winsorized data.

Author(s)

Andri Signorell <andri@signorell.net>

See Also

Winsorize from the package robustHD contains an option to winsorize multivariate data

scale, RobScale

Examples

## generate data
set.seed(1234)     # for reproducibility
x <- rnorm(10)     # standard normal
x[1] <- x[1] * 10  # introduce outlier

## Winsorize data
x
Winsorize(x)

# use Large and Small, if a fix number of values should be winsorized (here k=3):
Winsorize(x, minval=tail(Small(x, k=3), 1), maxval=head(Large(x, k=3), 1))

[Package DescTools version 0.99.24 Index]