qq.Plot {asbio}

Normal quantile plots for single or multiple factor levels

Description

Provides quantile plots for one or more factor levels overlaid on a single graph. If plot.CI = TRUE, then code for bootstrapped confidence provided in the documentation for boot is applied to create confidence envelopes. If plot.CI = FALSE, qqnorm and qqline are used to create overlaid normal probability plots given multiple categories in x.

Usage

qq.Plot(y, x = NULL, col = NULL, pch = NULL, main = "", R = 5000, fit.lty = 1, 
env.lty = 2, conf = 0.95, type = "point", ylim = NULL, xlim = NULL, xlab = NULL, 
ylab = NULL, plot.CI = FALSE, standy = TRUE, ...)

Arguments

y

The response variable

x

A categorical variable to subset y

col

A scalar or vector with length equivalent to the number of levels in x, describing colors of points and lines for levels in x.

pch

A scalar or vector with length equivalent to the number of levels in x, describing symbols for levels in x.

main

Main title.

R

Number of bootstrap samples for calculating confidence envelopes

fit.lty

Line type for fit line(s).

env.lty

Line type for fit line(s).

conf

Level of confidence in confidence envelopes.

type

Type of bootstrapped confidence envelope. One of "point" or "overall".

xlim

A two element vector defining the lower and upper x-axis limits .

ylim

A two element vector defining the lower and upper y-axis limits .

xlab

X-axis label.

ylab

Y-axis label.

plot.CI

Logical, specifying whether or not confidence ellipses should be plotted.

standy

Logical, specifying if observations should be standardized.

...

Other arguments from plot.

Author(s)

Ken Aho

See Also

qqnorm, qqline, envelope, boot

Examples

y <- rnorm(50)
x <- c(rep(1, 25), rep(2, 25))
qq.Plot(y, x)