HH (version 3.1-23)

hovBF: Homogeneity of Variance: Brown--Forsyth method

Description

Homogeneity of Variance: Brown--Forsyth method

Usage

hovBF(x, data = sys.parent(), ..., na.rm = TRUE)
hovplotBF(x, data, ..., na.rm = TRUE,
          main = "Brown-Forsyth Homogeneity of Variance", plotmath = TRUE)

Arguments

x

Model formula with one response variable and one factor.

data

data.frame

...

Other arguments. hovplotBF sends them on to the panel function. hovBF ignores them.

na.rm

A logical value indicating whether 'NA' values should be stripped before the computation proceeds. See median.

main

main title for the plot.

plotmath

Logical. When TRUE (the default) the strip labels use plotmath. When FALSE the strip labels use ASCII.

Value

• hovplotBF returns a three-panel trellis object. hovBF returns an htest object.

References

Brown, M.~B. and Forsyth, A.~B. (1974). ``Robust tests for equality of variances.'' Journal of the American Statistical Association, 69:364--367.

Examples

data(batch)
batch1.aov <- aov(Calcium ~ Batch, data=batch)
anova(batch1.aov)
hovBF(Calcium ~ Batch, data=batch)
hovplotBF(Calcium ~ Batch, data=batch)