gvlma (version 1.0.0.3)

plot.gvlmaDel: Various Plots for a Gvlmadel Object

Description

Plots to display the behavior of the deletion statistics stored in a gvlmaDel object.

Usage

# S3 method for gvlmaDel
plot(x, which = 1:2, TukeyStyle = TRUE, ask
= prod(par("mfcol")) < max(c(10, 5)[which]) && dev.interactive(),
pointlabels, …)

Arguments

x

A gvlmaDel object.

which

Vector indicating which, or both, of two types of plots to show.

TukeyStyle

If TRUE, determine unusual observations in a robust way based on inter-quartile ranges, else based on standard deviations.

ask

If TRUE, prompt the user before beginning a new page of graphs.

pointlabels

A vector of length the number of observations in the linear model fit in the gvlmaDel object containing character strings to be used as labels for unusual points.

…

Additional arguments that are ignored.

Value

No value is returned.

Details

If which = 1, each of the 5 deletion statistics (deletion global statistic and each of the 4 directional statistics) is plotted against the time sequence used for the 4th directional statistic (assessing heteroscedasticity).

If which = 2, the function display.delstats is called for each of the 5 deletion statistics. The argument TukeyStyle is passed directly to display.delstats. See the help for display.delstats for details.

If which = c(1,2), the default, then all 10 plots are generated.

The deletion statistics in the gvlmaDel object are the percent relative change when each observation, in turn, is omitted from the model fitting.

References

Pena, EA and Slate, EH (2006). “Global validation of linear model assumptions,” J.\ Amer.\ Statist.\ Assoc., 101(473):341-354.

See Also

gvlma, deletion.gvlma

Examples

# NOT RUN {
data(CarMileageData)
CarModelAssess <- gvlma(NumGallons ~ MilesLastFill + NumDaysBetw,
    data = CarMileageData)
CarModelDel <- deletion.gvlma(CarModelAssess)
par(mfrow=c(1,1))
plot(CarModelDel)
par(mfrow=c(2,2))
plot(CarModelDel)
plot(CarModelDel, TukeyStyle = FALSE)
plot(CarModelDel, which = 2)
# }