Boxplot {car}R Documentation

Boxplots With Point Identification

Description

Boxplot is a wrapper for the standard R boxplot function, providing point identification, axis labels, and a formula interface for boxplots without a grouping variable.

Usage

Boxplot(y, ...)

## Default S3 method:
Boxplot(y, g, labels, id.method = c("y", "identify", "none"), 
    id.n=10, xlab, ylab, ...)

## S3 method for class 'formula'
Boxplot(formula, data = NULL, subset, na.action = NULL, labels., 
    id.method = c("y", "identify", "none"), xlab, ylab, ...)

Arguments

y

a numeric variable for which the boxplot is to be constructed.

g

a grouping variable, usually a factor, for constructing parallel boxplots.

labels, labels.

point labels; if not specified, Boxplot will use the row names of the data argument, if one is given, or observation numbers.

id.method

if "y" (the default), all outlying points are labeled; if "identify", points may be labeled interactive; if "none", no point identification is performed.

id.n

up to id.n high outliers and low outliers will be identified in each group, (default, 10).

xlab, ylab

text labels for the horizontal and vertical axes; if missing, Boxplot will use the variable names.

formula

a ‘model’ formula, of the form ~ y to produce a boxplot for the variable y, or of the form y ~ g to produce parallel boxplots for y within levels of the grouping variable g, usually a factor.

data, subset, na.action

as for statistical modeling functions (see, e.g., lm).

...

further arguments to be passed to boxplot.

Author(s)

John Fox jfox@mcmaster.ca

References

Fox, J. and Weisberg, S. (2011) An R Companion to Applied Regression, Second Edition, Sage.

See Also

boxplot

Examples

Boxplot(~income, data=Prestige, id.n=Inf) # identify all outliers
Boxplot(income ~ type, data=Prestige)
with(Prestige, Boxplot(income, labels=rownames(Prestige)))
with(Prestige, Boxplot(income, type, labels=rownames(Prestige)))
[Package car version 2.0-12 Index]