| boxplot.matrix {graphics} | R Documentation | 
Interpreting the columns (or rows) of a matrix as different groups, draw a boxplot for each.
## S3 method for class 'matrix' boxplot(x, use.cols = TRUE, ...)
x | 
 a numeric matrix.  | 
use.cols | 
 logical indicating if columns (by default) or rows
(  | 
... | 
 Further arguments to   | 
A list as for boxplot.
Martin Maechler, 1995, for S+, then R package sfsmisc.
boxplot.default which already works nowadays with
data.frames; boxplot.formula, plot.factor which
work with (the more general concept) of a grouping factor.
## Very similar to the example in ?boxplot
mat <- cbind(Uni05 = (1:100)/21, Norm = rnorm(100),
             T5 = rt(100, df = 5), Gam2 = rgamma(100, shape = 2))
boxplot(mat, main = "boxplot.matrix(...., main = ...)",
        notch = TRUE, col = 1:4)