reliaR (version 0.01)

qq.gp.weibull: Quantile versus quantile (QQ) plot for the generalized power Weibull(GPW) distribution

Description

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

Usage

qq.gp.weibull(x, alpha.est, theta.est, main = " ", line.qt = FALSE, ...)

Arguments

x

vector of observations

alpha.est

estimate of the parameter alpha

theta.est

estimate of the parameter theta

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.gp.weibull() carries out a QQ plot for the generalized power Weibull(GPW).

References

Nikulin, M. and Haghighi, F.(2006). A Chi-squared test for the generalized power Weibull family for the head-and-neck cancer censored data, Journal of Mathematical Sciences, Vol. 133(3), 1333-1341.

Pham, H. and Lai, C.D.(2007). On recent generalizations of the Weibull distribution, IEEE Trans. on Reliability, Vol. 56(3), 454-458.

See Also

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

Examples

## Load data sets
data(repairtimes)
## Maximum Likelihood(ML) Estimates of alpha & theta for the data(repairtimes)
## Estimates of alpha & theta using 'maxLik' package
## alpha.est = 1.566093, theta.est = 0.355321

qq.gp.weibull(repairtimes, 1.566093, 0.355321, main = " ", line.qt = FALSE)