heplots (version 1.1-0)

plot.boxM: Plot Box's M test

Description

This function creates a simple dot chart showing the contributions (log determinants) of the various groups to Box's M test for equality of covariance matrices.

Usage

## S3 method for class 'boxM':
plot(x,
             gplabel = NULL,
             pch = c(16, 15), 
             cex = c(2, 2.5), 
             col = c("blue", "red"),  
             xlim,
             conf=0.95, method=2, bias.adj=TRUE, lwd=2,
             ...)

Arguments

x

A "boxM" object resulting from boxM

gplabel

character string used to label the group factor.

pch

a vector of two point symbols to use for the individual groups and the pooled data, respectively

cex

character size, a vector of length two for groups and pooled data

col

colors for point symbols, a vector of length two

xlim

x limits for the plot

conf

coverage for approximate confidence intervals, 0 <= conf="" <="" 1<="" code=""> ; use conf=0 to suppress these

method

confidence interval method; see logdetCI

bias.adj

confidence interval bias adjustment; see logdetCI

lwd

line width for confidence interval

...

Arguments passed down to dotchart.

See Also

boxM, logdetCI dotchart

Examples

# Iris data
res <- boxM(iris[, 1:4], iris[, "Species"])
plot(res, gplabel="Species")

# Skulls data
skulls.mod <- lm(cbind(mb, bh, bl, nh) ~ epoch, data=Skulls)
skulls.boxm <- boxM(skulls.mod)
plot(skulls.boxm, gplabel="Epoch")
plot(skulls.boxm, gplabel="Epoch", bias.adj=FALSE)