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>

### See Also

`boxplot`

### 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 0.99.26 Index]