flexhaz: Dynamic Failure Rate Distributions for Survival Analysis

Flexible framework for specifying survival distributions through their hazard (failure rate) functions. Define arbitrary time-varying hazard functions to model complex failure patterns including bathtub curves, proportional hazards with covariates, and other non-standard hazard behaviors. Provides automatic computation of survival, CDF, PDF, quantiles, and sampling. Implements the likelihood model interface for maximum likelihood estimation with right-censored and left-censored survival data.

Version:	0.5.0
Depends:	R (≥ 3.5.0)
Imports:	stats, numDeriv, algebraic.dist, likelihood.model, generics
Suggests:	knitr, rmarkdown, testthat (≥ 3.0.0)
Published:	2026-03-02
DOI:	10.32614/CRAN.package.flexhaz
Author:	Alexander Towell [aut, cre]
Maintainer:	Alexander Towell <queelius at gmail.com>
BugReports:	https://github.com/queelius/flexhaz/issues
License:	GPL (≥ 3)
URL:	https://github.com/queelius/flexhaz, https://queelius.github.io/flexhaz/
NeedsCompilation:	no
Materials:	README, NEWS
CRAN checks:	flexhaz results

Documentation:

Reference manual:	flexhaz.html , flexhaz.pdf
Vignettes:	Custom Derivatives for Maximum Likelihood Estimation (source, R code) Creating Custom Distributions (source, R code) Dynamic Failure Rate Distributions (source, R code) flexhaz: Hazard-First Survival Modeling (source, R code) Reliability Engineering Applications (source, R code)

Downloads:

Package source:	flexhaz_0.5.0.tar.gz
Windows binaries:	r-devel: flexhaz_0.5.0.zip, r-release: flexhaz_0.5.0.zip, r-oldrel: flexhaz_0.5.0.zip
macOS binaries:	r-release (arm64): flexhaz_0.5.0.tgz, r-oldrel (arm64): flexhaz_0.5.0.tgz, r-release (x86_64): flexhaz_0.5.0.tgz, r-oldrel (x86_64): flexhaz_0.5.0.tgz

Linking:

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