reliaR (version 0.01)

qq.weibull.ext: Quantile versus quantile (QQ) plot for the Weibull Extension(WE) distribution

Description

The function qq.weibull.ext() produces a QQ plot for the Weibull Extension(WE) based on their MLE or any other estimate. Also, a line going through the first and the third quartile can be sketched.

Usage

qq.weibull.ext(x, alpha.est, beta.est, main = " ", line.qt = FALSE, ...)

Arguments

x

vector of observations

alpha.est

estimate of the parameter alpha

beta.est

estimate of the parameter beta

main

the title for the plot

line.qt

logical; if TRUE, a line going by the first and third quartile is sketched.

...

additional arguments to be passed to the underlying plot function.

Value

The function qq.weibull.ext() carries out a QQ plot for the Weibull Extension(WE).

References

Tang, Y., Xie, M. and Goh, T.N., (2003). Statistical analysis of a Weibull extension model, Communications in Statistics: Theory & Methods 32(5):913-928.

Zhang, T., and Xie, M.(2007). Failure Data Analysis with Extended Weibull Distribution, Communications in Statistics-Simulation and Computation, 36(3), 579-592.

See Also

pp.weibull.ext for PP plot and ks.weibull.ext function;

Examples

## Load data sets
data(sys2)
## Maximum Likelihood(ML) Estimates of alpha & beta for the data(sys2)
## Estimates of alpha & beta using 'maxLik' package
## alpha.est = 0.00019114, beta.est = 0.14696242

qq.weibull.ext(sys2, 0.00019114, 0.14696242, main = " ", line.qt = FALSE)