display.delstats: Plot Deletion Statistics and Their P-Values for Assessment of...
In gvlma: Global Validation of Linear Models Assumptions

Description Usage Arguments Details Value Author(s) References See Also Examples

Creates a graph of the p-values associated with the deletion statistics versus the deletion statistics with unusual observations highlighted. This function is called by plot.gvlmaDel.

1 2	display.delstats(deletedStatvals, deletedpvals, nsd = 3, TukeyStyle = TRUE, statname = "G", pointlabels)

`deletedStatvals`	The vector of deletion statistics, with i-th entry defined as the percent relative change in the global test statistic when the i-th observation is removed from the analysis.
`deletedpvals`	The vector of p-values associated with the global test statistics, with i-th entry being the p-value for the global test statistic with observation i removed.
`nsd`	Parameter that governs which observations are deemed unusual. When `TukeyStyle = TRUE`, “control limits” are drawn `nsd` times the interquartile range beyond the quartiles for both the `deletedStatvals` and `deletedpvals`. When `TukeyStyle = FALSE`, “control limits” are drawn at `nsd` standard deviations away from the sample means. Observations beyond these “control limits” are marked and labeled using the text in pointlabels, if provided (else by observation number).
`TukeyStyle`	Controls how unusual observations are determined. If `TukeyStyle = TRUE` (default), then unusual observations are farther than `nsd` times the interquartile range from the quartiles (in either of the `deletedStatvals` and `deletedpvals` directions). If `TukeyStyle = FALSE`, then unusual observations are farther than `nsd` times the sample standard deviation from the sample mean.
`statname`	A string used to label the `deletedStatvals` axis of the plot. If missing, this label is determined from the variable name passed as the `deletedStatvals` argument, if possible; otherwise defaults to "Deleted statistics."
`pointlabels`	Character vector of same length as `deletedStatvals` and `deletedpvals` used for labelling unusual observations.

Generally display.delstats is not called directly, but rather by the function plot.gvlmaDel.

Plots the deletedpvals versus the deletedStatvals and adds “control limits” determined by the parameters nsd and TukeyStyle. Points outside the “control limits” (in either the deletedStatval or deletedpval) are labeled as unusual.

A dataframe consisting of the unusual observations with variables deletedStatval and deletedpval.

Slate, EH slate@stat.fsu.edu and Pena, EA pena@stat.sc.edu.

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

gvlma

data(CarMileageData)
CarMileageAssess <- gvlma(NumGallons ~ MilesLastFill + NumDaysBetw,
data = CarMileageData)
CarMileageDel <- deletion.gvlma(CarMileageAssess)
plot(CarMileageDel)
display.delstats(CarMileageDel$DeltaGlobalStat, CarMileageDel$GStatpvalue)
display.delstats(CarMileageDel$DeltaStat1, CarMileageDel$Stat1pvalue)