extRemes (version 2.1-1)

shiftplot: Shift Plot Between Two Sets of Data

Description

A shift plot is a plot of the quantiles of a data set y minus those of another data set x against those of x. Includes 95 percent simultaneous confidence bands.

Usage

shiftplot(x, y, pch = 20, xlab = "x Quantiles", ylab = "y Quantiles", main = NULL, ...)

Arguments

x

numeric vector of length m.

y

numeric vector of length n.

pch

Plotting character.

xlab

Character string giving abscissa axis label.

ylab

Character string giving ordinate axis label.

main

Character string giving plot title.

…

Other optional arguments to plot function.

Value

No value is returned, but a plot is created.

Details

The shift plot is a graph of y_q - x_q vs. x_q, where y_q and x_q denote the quantiles of x and y, resp. 95 percent simultaneous confidence bands are calculated per Doksum and Sievers (1976). The primary usage of this plot is where x is a control group and y is an experimental method; or something similar. For example, x might represent observations, and y might represent climate model output; or some such.

References

Doksum, K. A. and Sievers, G. L. (1976) Plotting with confidence: graphical comparisons of two populations. Biometrika, 63, (3), 421--434.

See Also

qqplot, qqnorm, approxfun

Examples

# NOT RUN {
z <- rnorm( 100)
y <- rexp(30)
shiftplot( z, y)

data( ftcanmax)
shiftplot( y, ftcanmax[,"Prec"])
# }