R: Box Plot Statistics

boxplot.stats {base}

R Documentation

Box Plot Statistics

Description

This function is typically is called by boxplot to gather the statistics necessary for producing box plots, but may be invoked separately.

Usage

boxplot.stats(x, coef = 1.5, do.conf=TRUE, do.out=TRUE)

Arguments

x

a numeric vector for which the boxplot will be constructed (NAs and NaNs are allowed and omitted).

coef

this determines how far the plot “whiskers” extend out from the box. If coef is positive, the whiskers extend to the most extreme data point which is no more than coef times the interquartile coef from the box. A value of zero causes the whiskers to extend to the data extremes.

do.conf, do.out

logicals; if FALSE, the conf or out component respectively will be empty in the result.

Value

List with named components as follows:

stats

a vector of length 5, containing the extreme of the lower whisker, the lower “hinge”, the median, the upper “hinge” and the extreme of the upper whisker.

n

the number of of non-NA observations in the sample.

conf

the lower and upper extremes of the “notch”.

out

the values of any data points which lie beyond the extremes of the whiskers.

Note that $stats and $conf are sorted in increasing order, unlike S, and that $n and $out include any +- Inf values.

Examples

x <- c(1:100, 1000)
str(boxplot.stats(x))
str(boxplot.stats(x, do.conf=FALSE, do.out=FALSE))
str(boxplot.stats(x, coef = 3, do.conf=FALSE))
str(boxplot.stats(x, coef = 0))

str(boxplot.stats(c(x, NA)))
str(boxplot.stats(c(x, -1:1/0)))