DAAG: qreference – R documentation

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qreference

Normal QQ Reference Plot

Description

This function computes the normal QQ plot for given data and allows for comparison with normal QQ plots of simulated data.

Usage

qreference(test = NULL, m = 50, nrep = 6, distribution = function(x) qnorm(x, 
    mean = ifelse(is.null(test), 0, mean(test)), sd = ifelse(is.null(test), 
    1, sd(test))), seed = NULL, nrows = NULL, cex.strip = 0.75, 
    xlab = NULL, ylab = NULL)

Arguments

`test`	a vector containing a sample to be tested; if not supplied, all qq-plots are of the reference distribution
`m`	the sample size for the reference samples; default is test sample size if test sample is supplied
`nrep`	the total number of samples, including reference samples and test sample if any
`distribution`	reference distribution; default is standard normal
`seed`	the random number generator seed
`nrows`	number of rows in the plot layout
`cex.strip`	character expansion factor for labels
`xlab`	label for x-axis
`ylab`	label for y-axis

Value

QQ plots of the sample (if test is non-null) and all reference samples

Author(s)

J.H. Maindonald

Examples

# qreference(rt(180,1))

# qreference(rt(180,1), distribution=function(x) qt(x, df=1))

# qreference(rexp(180), nrep = 4)

# toycars.lm <- lm(distance ~ angle + factor(car), data = toycars)
# qreference(residuals(toycars.lm), nrep = 9)

DAAG

Data Analysis and Graphics Data and Functions

v1.24

GPL-3

Authors

John H. Maindonald and W. John Braun

Initial release