weibullness (version 1.24.1)

wp.plot: Weibull Plot

Description

wp.plot produces a Weibull 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 plot is based on taking the logarithm of the Weibull cumulative distribution function twice. The horizontal axis is logarithmic.

See Also

plot, qqnorm, qqplot, iwp.plot, ep.plot.
bs.plot for the Birnbaum-Saunders probability plot in package bsgof.

Examples

attach(Wdata)

wp.plot(bearings)

# With cosmetic lines 
wp.plot(bearings, main="Weibull 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 )