rgr: gx.add.chisq – R documentation

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gx.add.chisq

Function to Add Fences to Chi-square Plots

Description

This is an internal function used to plot fences at stated probability levels on a Chi-square plot to assist in the assessment of the plotted distribution. By default fences are plotted for the 90th, 95th and 98th percentiles of the Chi-square distribution. The function is called from gx.md.plt0, itself called from gx.md.plot that is used to display Chi-square plots generated by gx.mva, gx.mva.closed, gx.robmva, gx.robmva.closed, gx.md.gait amd gx.md.gait.closed.

Usage

gx.add.chisq(p = c(0.98, 0.95, 0.9), df = NULL, ifflip = FALSE,
	cex = 0.6)

Arguments

`p`	the percentiles of the Chi-square distribution for the fences to be displayed, by default the 90th, 95th and 98th percentiles. If no fences are required set `p = NULL`.
`df`	the degrees of freedom for the Chi-square distribution, the number of variables in the multivariate distribution.
`ifflip`	by default fence labelling is placed to the left of the fences just above the x-axis. Setting `ifflip = TRUE` places the annotation to the right.
`cex`	the scale expansion factor for the fence labelling, by default `cex = 0.6`.

Author(s)

Robert G. Garrett

Examples

##  Synthesize test data
test <- mvrnorm(100, mu = c(40 ,30),Sigma = matrix(c(6, 3, 3, 2), 2, 2))

## Display annotated Chi-square plot
gx.md.gait(test)
gx.md.gait(test, ifadd = c(0.9, 0.98))

## Clean-up
rm(test)

rgr

Applied Geochemistry EDA

v1.1.15

GPL-2

Authors

Robert G. Garrett

Initial release

2018-03-05