Package: stagelife
Type: Package
Title: Random Number Generation and Inferences for Two-Stage
        Life-Testing Data
Version: 0.1.0
Authors@R: person("Vikas Kumar", "Sharma", email = "vksharma@bhu.ac.in", role = c("aut", "cre"))
Description: Provides random number generation, estimation, and
        hypothesis testing for two-stage life-testing experiments in
        which units begin on a baseline stress and, at a fixed or
        random change point, some or all surviving units move to an
        elevated stress ("stage life testing"), following the
        cumulative-exposure model of Laumen and Cramer (2019), "Stage
        life testing", <doi:10.1002/nav.21874>. Twelve baseline
        lifetime distributions are supplied (Weibull, Power Lindley,
        Exponentiated Lindley, Exponentiated Exponential,
        Marshall-Olkin Exponential, Lomax, Exponentiated Teissier,
        Log-Logistic, Chen, Log-normal, Gamma, and Power Muth/Power
        Teissier) together with three parameter-sharing cases
        ('common', 'shape1', 'shape11'). The package implements data
        simulation under both the fixed-proportion 'typeP' and
        fixed-count 'typeM' rules and the simple-step-stress special
        case, maximum likelihood estimation using a hybrid
        'Nelder-Mead' and 'BFGS' optimisation routine, asymptotic
        (Wald) and non-parametric/parametric bootstrap confidence
        intervals (including log-scale variants that guarantee a
        positive interval), a stage-1-observation planning probability,
        Kolmogorov-Smirnov goodness-of-fit testing with a
        parametric-bootstrap correction for estimated parameters,
        likelihood-ratio and information criteria for nested/non-nested
        model comparison, and diagnostic plots comparing fitted and
        empirical distributions, including the cumulative distribution
        function (CDF), survival function, probability-probability
        (P-P), and quantile-quantile (Q-Q) plots.
License: MIT + file LICENSE
Encoding: UTF-8
LazyData: true
Depends: R (>= 4.1.0)
Imports: compiler, ggplot2, graphics, lamW, parallel, stats
Suggests: knitr, rmarkdown, testthat (>= 3.0.0)
VignetteBuilder: knitr
Config/testthat/edition: 3
URL: https://github.com/vksharma-bhu/stagelife
BugReports: https://github.com/vksharma-bhu/stagelife/issues
Config/roxygen2/version: 8.1.0
Roxygen: list(markdown = TRUE)
NeedsCompilation: no
Packaged: 2026-11-05 00:59:25 UTC; root
Author: Vikas Kumar Sharma [aut, cre]
Maintainer: Vikas Kumar Sharma <vksharma@bhu.ac.in>
Config/pak/sysreqs: cmake make
Repository: https://vksharma-bhu.r-universe.dev
Date/Publication: 2026-09-30 02:08:38 UTC
RemoteUrl: https://github.com/vksharma-bhu/stagelife
RemoteRef: HEAD
RemoteSha: 677a8854152460b6044b7e1d25889e861128b7e4