R: Outlier

Outlier {DescTools}

R Documentation

Outlier

Description

Return outliers following Tukey's boxplot definition.

Usage

Outlier(x, method = c("boxplot"), value = TRUE,na.rm = FALSE)

Arguments

`x`	a (non-empty) numeric vector of data values.
`method`	the method to be used. So far only Tukey's boxplot rule is implemented.
`value`	logical. If `FALSE`, a vector containing the (integer) indices of the outliers is returned, and if `TRUE` (default), a vector containing the matching elements themselves is returned.
`na.rm`	logical. Should missing values be removed? Defaults to `FALSE`.

Details

Outlier detection is a tricky problem and should be handled with care. We implement only Tukey's boxplot rule as a rough idea of spotting extreme values.

Value

the values of x lying outside the whiskers in a boxplot or the indices of them

Author(s)

Andri Signorell <andri@signorell.net>

Examples

Outlier(d.pizza$temperature, na.rm=TRUE)

# it's the same as the result from boxplot
sort(d.pizza$temperature[Outlier(d.pizza$temperature, value=FALSE, na.rm=TRUE)])
b <- boxplot(d.pizza$temperature, plot=FALSE)
sort(b$out)

# nice to find the corresponding rows
d.pizza[Outlier(d.pizza$temperature, value=FALSE, na.rm=TRUE), ]


# outliers for the each driver
tapply(d.pizza$temperature, d.pizza$driver, Outlier, na.rm=TRUE)

# the same as:
boxplot(temperature ~ driver, d.pizza)$out

[Package DescTools version 0.99.38 Index]