# qq.lfr: Quantile versus quantile (QQ) plot for the linear failure... In reliaR: Package for some probability distributions.

## Description

The function `qq.lfr()` produces a QQ plot for the linear failure rate(LFR) based on their MLE or any other estimate. Also, a line going through the first and the third quartile can be sketched.

## Usage

 `1` ```qq.lfr(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.lfr()` carries out a QQ plot for the linear failure rate(LFR).

## References

Bain, L.J. (1974). Analysis for the Linear Failure-Rate Life-Testing Distribution, Technometrics, 16(4), 551 - 559.

Lawless, J.F.(2003). Statistical Models and Methods for Lifetime Data, John Wiley and Sons, New York.

Sen, A. and Bhattacharya, G.K.(1995). Inference procedure for the linear failure rate mode, Journal of Statistical Planning and Inference, 46, 59-76.

`pp.lfr` for `PP` plot and `ks.lfr` function;
 ```1 2 3 4 5 6 7``` ```## 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 = 1.77773e-03, beta.est = 2.77764e-06 qq.lfr(sys2, 1.777673e-03, 2.777640e-06, main = " ", line.qt = FALSE) ```