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Help to Fit of a Parametric Distribution to Non-Censored or Censored Data

fitdistrplus extends the fitdistr() function (of the MASS package) with several functions to help the fit of a parametric distribution to non-censored or censored data. Censored data may contain left censored, right censored and interval censored values, with several lower and upper bounds. In addition to maximum likelihood estimation (MLE), the package provides moment matching (MME), quantile matching (QME) and maximum goodness-of-fit estimation (MGE) methods (available only for non-censored data). Weighted versions of MLE, MME and QME are available.

fitdistrplus allows to fit any probability distribution provided by the user and not restricted to base R distributions (see ?Distributions). We strongly encourage users to visit the CRAN task view on Distributions proposed by Dutang, Kiener & Swihart (2024).

The package

The stable version of fitdistrplus can be installed from CRAN using:

install.packages("fitdistrplus")

The development version of fitdistrplus can be installed from GitHub (remotes needed):

if (!requireNamespace("remotes", quietly = TRUE))
   install.packages("remotes")
   
remotes::install_github("lbbe-software/fitdistrplus")

Finally load the package in your current R session with the following R command:

require("fitdistrplus")

Documentation

Four vignettes are attached to the fitdistrplus package. Two of them are for beginners

  • Overview of the fitdistrplus package
  • Frequently Asked Questions

The last two vignettes deal with advanced topics

  • Which optimization algorithm to choose?
  • Starting values used in fitdistrplus

Authors & Contacts

Please read the FAQ before contacting authors

  • Marie-Laure Delignette-Muller: marielaure.delignettemuller<<@))vetagro-sup.fr
  • Christophe Dutang: dutangc<<@))gmail.com
  • Aurélie Siberchicot: aurelie.siberchicot<<@))univ-lyon1.fr

Issues can be reported on fitdistrplus-issues.

Citation

If you use fitdistrplus, you should cite: Marie Laure Delignette-Muller, Christophe Dutang (2015). fitdistrplus: An R Package for Fitting Distributions. Journal of Statistical Software. https://www.jstatsoft.org/article/view/v064i04 DOI 10.18637/jss.v064.i04.

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Version

Install

install.packages('fitdistrplus')

Monthly Downloads

54,097

Version

1.2-5

License

GPL (>= 2)

Issues

Pull Requests

Stars

Forks

Maintainer

Aurélie Siberchicot

Last Published

January 22nd, 2026

Functions in fitdistrplus (1.2-5)

detectbound

Detect bounds for density function
gofstat

Goodness-of-fit statistics
fluazinam

Species-Sensitivity Distribution (SSD) for Fluazinam
graphcomp

Graphical comparison of multiple fitted distributions (for non-censored data)
fitdistrplus-package

Overview of the fitdistrplus package
logLikplot

(Log)likelihood plot for a fit using maximum likelihood
graphcompcens

Graphical comparison of multiple fitted distributions for censored data
fitdistcens

Fitting of univariate distributions to censored data
logLiksurface

(Log)likelihood surfaces or (log)likelihood curves
groundbeef

Ground beef serving size data set
fremale

Fictive survival dataset of a french Male population
mgedist

Maximum goodness-of-fit fit of univariate continuous distributions
qmedist

Quantile matching fit of univariate distributions
prefit

Pre-fitting procedure
quantile

Quantile estimation from a fitted distribution
plotdist

Plot of empirical and theoretical distributions for non-censored data
msedist

Maximum spacing estimation of univariate distributions
mmedist

Matching moment fit of univariate distributions
salinity

Species-Sensitivity Distribution (SSD) for salinity tolerance
mledist

Maximum likelihood fit of univariate distributions
smokedfish

Contamination data of Listeria monocytogenes in smoked fish
toxocara

Parasite abundance in insular feral cats
plotdistcens

Plot of empirical and theoretical distributions for censored data
CIcdfplot

Empirical cumulative distribution function with pointwise confidence intervals on probabilities or on quantiles
dataFAQ

Datasets for the FAQ
bootdist

Bootstrap simulation of uncertainty for non-censored data
fitdist

Fit of univariate distributions to non-censored data
danish

Danish reinsurance claim dataset
bootdistcens

Bootstrap simulation of uncertainty for censored data
Surv2fitdistcens

Handling of data formated as in the survival package for use in fitdistcens()
descdist

Description of an empirical distribution for non-censored data
endosulfan

Species Sensitivity Distribution (SSD) for endosulfan