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, ...)

Value

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

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.

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.

Examples

Run this code

## 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)