weibullness (version 1.23.8)

wp.plot: Weibull Probability Plot

Description

wp.plot produces a Weibull probability plot.

Usage

wp.plot(x, plot.it=TRUE, a, col.line="black", lty.line=1, 
        xlim=NULL, ylim=NULL, main=NULL, sub=NULL, xlab=NULL, ylab="Probability", ...)

Value

A list with the following components:

x

The sorted data

y

log(-log(1-ppoints(n,a=a)))

Arguments

x

a numeric vector of data values. Missing values are allowed.

plot.it

logical. Should the result be plotted?

a

the offset fraction to be used; typically in (0,1). See ppoints.

col.line

the color of the straight line.

lty.line

the line type of the straight line.

xlim

the x limits of the plot.

ylim

the y limits of the plot.

main

a main title for the plot, see also title.

sub

a sub title for the plot.

xlab

a label for the x axis, defaults to a description of x.

ylab

a label for the y axis, defaults to "Probability".

...

graphical parameters.

Author

Chanseok Park

Details

The Weibull probability plot is based on taking the logarithm of the Weibull cumulative distribution function twice

See Also

plot, qqnorm, qqplot.

Examples

attach(Wdata)

wp.plot( bearings )

# With cosmetic lines 
wp.plot(bearings, main="Weibull Probability Plot", col.line="red", 
        xlab="Lifetimes of bearings", lty.line=1, pch=3)
hline = log(-log(1- c( (1:5)/100, (1:9)/10)  ))
abline( h=hline, col=gray(0.1), lty=3, lwd=0.5 )
abline( v=  seq(15, 200,by=5), col=gray(0.1), lty=3, lwd=0.5 )