Maintainer: | Christophe Dutang, Patrice Kiener, Bruce J. Swihart |
Contact: | dutangc at gmail.com |
Version: | 2023-11-12 |
URL: | https://CRAN.R-project.org/view=Distributions |
Source: | https://github.com/cran-task-views/Distributions/ |
Contributions: | Suggestions and improvements for this task view are very welcome and can be made through issues or pull requests on GitHub or via e-mail to the maintainer address. For further details see the Contributing guide. |
Citation: | Christophe Dutang, Patrice Kiener, Bruce J. Swihart (2023). CRAN Task View: Probability Distributions. Version 2023-11-12. URL https://CRAN.R-project.org/view=Distributions. |
Installation: | The packages from this task view can be installed automatically using the ctv package. For example, ctv::install.views("Distributions", coreOnly = TRUE) installs all the core packages or ctv::update.views("Distributions") installs all packages that are not yet installed and up-to-date. See the CRAN Task View Initiative for more details. |
For most of the classical distributions, base R provides probability distribution functions (p), density functions (d), quantile functions (q), and random number generation (r). Beyond this basic functionality, many CRAN packages provide additional useful distributions. In particular, multivariate distributions as well as copulas are available in contributed packages.
The maintainers gratefully acknowledge Achim Zeileis, David Luethi, Tobias Verbeke, Robin Hankin, Mathias Kohl, G. Jay Kerns, Kjetil Halvorsen, William Asquith for their useful comments/suggestions. If you think information is not accurate or not complete, please send an e-mail to the maintainer or submit an issue or pull request in the GitHub repository linked above.
p
foo()
density functions d
foo()
, quantile functions q
foo()
, and random number generation r
foo()
where foo indicates the type of distribution: beta (foo = beta
), binomial binom
, Cauchy cauchy
, chi-squared chisq
, exponential exp
, Fisher F f
, gamma gamma
, geometric geom
, hypergeometric hyper
, logistic logis
, lognormal lnorm
, negative binomial nbinom
, normal norm
, Poisson pois
, Student t t
, uniform unif
, Weibull weibull
. Following the same naming scheme, but somewhat less standard are the following distributions in base R: probabilities of coincidences (also known as “birthday paradox”) birthday
(only p and q), studentized range distribution tukey
(only p and q), Wilcoxon signed rank distribution signrank
, Wilcoxon rank sum distribution wilcox
.ks.test
, shapiro.test
, ansari.test
, chisq.test
, poisson.test
. Ecume provides non-parametric two-sample (or k-sample) distribution comparisons in the univariate or multivariate case allowing observation weights and thresholds.Some packages may optionally provide the symbolic derivatives with respect to the parameters for the probability functions. For instance, the first and second derivatives of the log-density can be of some help in estimation and inference tasks, and the derivatives of the quantile function can help when inferring on a given quantile. For that purpose, the following base R functions can be used stats::D()
for derivatives w.r.t. a single parameter, or stats::deriv()
for (partial) derivatives w.r.t. multiple parameters. The Deriv package provides a much more flexible symbolic differentiation interface. One can also use Stan Math library through StanHeaders package, see e.g. this blog. The nieve package provides symbolic differentiation for two probability distribution (Generalized Pareto and Generalized Extreme Value) in order to compute the log-likelihood for example.
Binomial (including Bernoulli) distribution: provided in stats. Zero-modified, zero-inflated, truncated versions are provided in gamlss.dist, extraDistr, actuar and in VGAM. LaplacesDemon provides dedicated functions for the Bernoulli distribution. rmutil provides the double binomial and the multiplicative binomial distributions.
Distribution name | Packages | Functions | Distribution suffix |
binomial | stats | d , p , q , r | binom |
zero-infl. binomial | extraDistr | d , p , q , r | zib |
zero-infl. binomial | VGAM | d , p , q , r | zibinom |
zero-infl. binomial | gamlss.dist | d , p , q , r | ZIBI |
zero mod. binomial | VGAM | d , p , q , r | zabinom |
zero mod. binomial | actuar | d , p , q , r | zmbinom |
zero mod. binomial | gamlss.dist | d , p , q , r | ZABI |
zero trunc. binomial | actuar | d , p , q , r | ztbinom |
trunc. binomial | extraDistr | d , p , q , r | tbinom |
sum,cumsum,sample
and is provided in extraDistr.Zipf distribution and extensions: d, p, q, r functions of the Zipf and the Zipf-Mandelbrot distributions are provided in tolerance, VGAM. Package zipfR provides tools for distribution of word frequency, such as the Zipf distribution. zipfextR provides three extensions of the Zipf distribution: the Marshall-Olkin Extended Zipf, the Zipf-Poisson Extreme and the Zipf-Poisson Stopped Sum distributions.
Beta distribution and its extensions: Base R provides the d, p, q, r functions for this distribution (see above). extraDistr provides the beta distribution parametrized by the mean and the precision. actuar provides moments and limited expected values. sadists implements Gram Charlier, Edgeworth and Cornish-Fisher approximations for doubly non central beta distribution for computing d, p, q, r functions. extraDistr provides the four-parameter beta with lower and upper bounds. The generalized beta of the first kind (GB1) (exponentiation of beta 1) is provided in gamlss.dist, mbbefd, actuar. betafunctions provides the four-parameter beta (that is with location and scale parameters), the beta parametrized by the mean and the variance as well as the beta compound beta distribution. The beta prime (or beta of the second kind), which is the distribution of X/(1-X) when X follows a beta distribution of the first kind, is provided in VGAM, extraDistr, LaplacesDemon and mc2d. The zero and one inflated beta distribution can be found in gamlss.dist. The generalized beta of the second kind (GB2) is provided in gamlss.dist, GB2. Several special cases of the generalized beta distribution are also implemented in VGAM, mc2d: Lomax, inverse Lomax, Dagum, Singh-Maddala, Pert distributions. actuar provides the Feller-Pareto distribution as special cases Burr, loglogistic, paralogistic, generalized Pareto, Pareto, see also the Pareto subsection. llogistic provides the log-logistic parametrized by the median.
Distribution name | Packages | Functions | Distribution suffix |
Beta (1st kind) | stats | d, p, q, r | beta |
Beta | actuar | m, mgf, lev | beta |
Beta | betafunctions | d, p, q, r | Beta.4P |
Doubly non central beta | sadists | d, p, q, r | nbeta |
4-param beta | extraDistr | d, p, q, r | nsbeta |
zero-infl beta | gamlss.dist | d, p, q, r | BEZI |
one-infl beta | gamlss.dist | d, p, q, r | BEOI |
one-infl beta | mbbefd | d, p, q, r, m, ec | oibeta |
GB1 | gamlss.dist | d, p, q, r | GB1 |
GB1 | mbbefd | d, p, q, r, m, ec | gbeta |
GB1 | actuar | d, p, q, r, m, lev | genbeta |
one-infl GB1 | mbbefd | d, p, q, r, m, ec | oigbeta |
Distribution name | Packages | Functions | Distribution suffix |
Beta (2nd kind) | VGAM | d, p, q, r | beta |
Beta (2nd kind) | extraDistr | d, p, q, r | invbeta |
Beta (2nd kind) | LaplacesDemon | d, r | betapr |
GB2 | VGAM | d, p, q, r | genbetaII |
GB2 | gamlss.dist | d, p, q, r | GB2 |
GB2 | GB2 | d, p, q, r | gb2 |
Trans beta 2 | actuar | d, p, q, r, m, lev | trbeta |
Chi(-squared or not) distribution: Base R provides the d, p, q, r functions for the chi-squared distribution, both central and non-central (see above). Moments, limited expected values and the moment generating function are provided in actuar. extraDistr provides d, p, q, r functions for inverse chi-squared distribution (standard and scaled). Only d,r functions are available for the inverse chi-squared distribution in package LaplacesDemon. A fast random generator is available for the Chi distribution is implemented in Runuran as well as the density function. The non-central Chi distribution is not yet implemented. The chi-bar-squared distribution is implemented in emdbook. sadists implements Gram Charlier, Edgeworth and Cornish-Fisher approximations for sums of non central chi-squared raised to powers distribution and sums of log of non central chi-squared for computing d, p, q, r functions.
Distribution name | Packages | Functions | Distribution suffix |
Chi-squared | stats | d, p, q, r | chisq |
Chi-squared | actuar | m, mgf, lev | chisq |
Chi-squared | Runuran | d, r | chisq |
Chi-bar-squared | emdbook | d, p, q, r | chibarsq |
Chi | Runuran | d, r | chi |
Inverse Chi-squared | extraDistr | d, p, q, r | invchisq |
Scaled Inverse Chi-squared | extraDistr | d, p, q, r | invchisq |
Sum of power Chi-squared | sadists | d, p, q, r | sumchisqpow |
Sum of log Chi-squared | sadists | d, p, q, r | sumlogchisq |
Exponential distribution and its extensions: Base R provides the d, p, q, r functions for this distribution (see above). actuar provides additional functions such as the moment generating function, moments and limited expected values. It also has the d, p, q, r for the inverse exponential distribution. The shifted (or two-parameter exponential) and the truncated exponential distributions are implemented in lmomco and tolerance packages with d, p, q, r functions. Exponential Power distribution is also known as General Error Distribution: d, p, q, r functions for the power and the skew power exponential type 1-4 distributions are implemented in gamlss.dist and lmomco. The power exponential distribution is also provided in normalp, rmutil, LaplacesDemon. The skew power exponential is provided mixSPE. A fast random generator is available for the power Exponential distribution is implemented in Runuran as well as the density function. AEP implements the Asymmetric Exponential Power Distribution.
Distribution name | Packages | Functions | Distribution suffix |
Exponential | stats | d, p, q, r | exp |
Exponential | actuar | m, mgf, lev | exp |
Exponential | gamlss.dist | d, p, q, r | EXP |
Exponential | poweRlaw | d, p, q, r | exp |
Inverse exponential | actuar | d, p, q, r, m, lev | invexp |
Shifted exponential | lmomco | d, p, q, r, lm, tlmr | exp |
Shifted exponential | tolerance | d, p, q, r | 2exp |
Truncated exponential | lmomco | d, p, q, r, lm, tlmr | texp |
Truncated exponential | ReIns | d, p, q, r | texp |
Power exponential | normalp | d, p, q, r | normp |
Power exponential | Runuran | d, r | exp |
Power exponential | rmutil | d, r | powexp |
Power exponential | LaplacesDemon | d, p, q, r | pe |
Skew power exp. | lmomco | d, p, q, r, lm, tlmr | aep4 |
Power and skew power exp. | mixSPE | r | pe, spe |
Power and skew power exp. | gamlss.dist | d, p, q, r | PE, SEP |
Gamma distribution and its extensions: Base R provides the d, p, q, r functions for this distribution (see above). EnvStats provides d, p, q, r functions of the gamma parametrized by the mean and the coefficient of variation. actuar provides d, p, q, r functions of the inverse, the inverse transformed and the log gamma distributions while ghyp provides those functions for the variance gamma distribution. extraDistr and LaplacesDemon provide the inverse gamma distribution. CaDENCE provides the zero-inflated gamma distribution. VarianceGamma provides d, p, q, r functions for the variance gamma distribution as well as moments (skewness, kurtosis, ...). VGAM, ggamma provide d, p, q, r functions of the log gamma and the generalized gamma distribution. The generalized gamma distribution can also be found in gamlss.dist. See Pearson III for a three-parameter gamma distribution with a location parameter. flexsurv provides d, p, q, r functions as well as hazard (h) and integrated hazard rate (i) functions for the generalized gamma distribution. coga provides d, p, r functions for a sum of independent but not identically distributed gamma distributions. MCMCpack provides d, r functions of the Inverse Gamma. rmutil provides the generalized Gamma. distTails provides the full-tail gamma distribution sglg provides the generalized log-Gamma along with various functions to fit semi-parametric regression models. ollggamma provides d, p, q, r for the Odd Log-Logistic Generalized Gamma.
Distribution name | Packages | Functions | Distribution suffix |
Gamma | stats | d, p, q, r | gamma |
Gamma | actuar | m, mgf, lev | gamma |
Gamma | EnvStats | d, p, q, r | gammaAlt |
zero-inflated Gamma | CaDENCE | d, p, q, r | bgamma |
Inverse gamma | actuar | d, p, q, r, m, lev, mgf | invgamma |
Inverse gamma | extraDistr | d, p, q, r | invgamma |
Inverse gamma | LaplacesDemon | d, r | invgamma |
Inverse gamma | MCMCpack | d, r | invgamma |
Log-gamma | actuar | d, p, q, r, m, lev | lgamma |
Log-gamma | VGAM | d, p, q, r | lgamma |
Variance gamma | ghyp | d, p, q, r | VG |
Variance gamma | VarianceGamma | d, p, q, r, m | vg |
Generalized gamma | flexsurv | d, p, q, r, h, i | gengamma |
Generalized gamma | gamlss.dist | d, p, q, r | GG |
Generalized gamma | VGAM | d, p, q, r | gengamma.stacy |
Generalized gamma | rmutil | d, p, q, r | ggamma |
Generalized gamma | ggamma | d, p, q, r | ggamma |
convolution of gamma | coga | d, p, r | coga |
Full-taill gamma | distTails | d, p, r | dFTG |
Generalized log-gamma | sglg | d, p, q, r | glg |
Pólya–Gamma distribution: r function random sampling routines for the distribution are provided by BayesLogit, pg, and pgdraw.
Gaussian (or normal) distribution and its extensions: Base R provides the d, p, q, r functions for this distribution (see above). actuar provides the moment generating function and moments. The truncnorm package provides d, p, q, r functions for the truncated gaussian distribution as well as functions for the first two moments. EnvStats provides d, p, q, r functions for the truncated normal distribution and the zero-modified distribution. extraDistr provides the truncated normal. LaplacesDemon provides d, p, q, r functions for the Half-normal distribution. The wrapped normal distribution is provided in CircStats. lmomco implements the generalized normal distribution. The Exponentially modified Gaussian is available in emg and gamlss.dist sn implements the skew normal distribution. greybox implements the folded normal distribution. VGAM implements the folded and the skewed normal distribution, and csn provides d, r functions for the closed skew normal distribution. NormalLaplace provides d, p, q, r functions for the sum of a normal and a Laplace random variables, while LaplacesDemon provides d, r functions of the sum of a normal and a Laplace random variables. PSDistr provides d, p, q, r functions of transformations of the normal distribution, such as expnormal and sinh-normal distributions.
Distribution name | Packages | Functions | Distribution suffix |
Normal | stats | d, p, q, r | norm |
Normal | actuar | m, mgf | norm |
Truncated normal | truncnorm | d, p, q, r, m | truncnorm |
Truncated normal | EnvStats | d, p, q, r | normTrunc |
Truncated normal | extraDistr | d, p, q, r | tnorm |
Truncated normal | crch | d, p, q, r | cnorm |
Generalized normal | lmomco | d, p, q, r | gno |
Zero modified Gaussian | EnvStats | d, p, q, r | zmnorm |
Exponentially modified Gaussian | emg | d, p, q, r | emg |
Exponentially modified Gaussian | gamlss.dist | d, p, q, r | exGAUSS |
Folded and skew normal | gamlss.dist | d, p, q, r | SN1, SN2 |
Folded normal | greybox | d, p, q, r | fnorm |
Closed skew normal | csn | d, p, q, r | csn |
Skew normal | sn | d, p, q, r | sn |
Logistic distribution and its extensions: Base R provides the d, p, q, r functions for this distribution (see above). actuar and VGAM provide d, p, q, r functions for the log logistic (also called Fisk), the paralogistic and the inverse paralogistic distributions. FAdist the log-logistic distribution with two and three parameters. The generalized logistic distribution (Type I, also known as skew-logistic distribution) is provided in lmomco, sld, rmutil, SCI and glogis. GTDL implements generalized Time-Dependent Logistic distribution.
Distribution name | Packages | Functions | Distribution suffix |
Logistic | stats | d, p, q, r | logis |
Logistic | actuar | m, mgf | logis |
Log logistic | actuar | d, p, q, r, m, lev | llogis |
Log logistic | VGAM | d, p, q, r | fisk |
Log logistic | FAdist | d, p, q, r | llog, llog3 |
Paralogistic | actuar | d, p, q, r, m, lev | paralogis |
Paralogistic | VGAM | d, p, q, r | paralogistic |
Inv. paralogistic | actuar | d, p, q, r, m, lev | invparalogis |
Inv. paralogistic | VGAM | d, p, q, r | inv.paralogistic |
Truncated logistic | crch | d, p, q, r | tlogis |
Generalized logistic | glogis | d, p, q, r | glogis |
Generalized logistic | SCI | d, p, q | genlog |
Generalized logistic | lmomco | d, p, q, r | glo |
Generalized logistic | sld | d, p, q, r | sl |
Generalized logistic | rmutil | d, p, q, r | glogis |
Pareto distribution: d, p, q, r functions are implemented in VGAM for the Pareto distribution type IV (which includes Burr’s distribution, Pareto type III, Pareto type II (also called the lomax distribution) and Pareto type I) and the (upper/lower) truncated Pareto distribution. In an actuarial context, actuar provides d, p, q, r functions as well as moments and limited expected values for the Pareto I and II, the inverse Pareto, the ‘generalized pareto’ distributions, the Burr and the inverse Burr distributions, all special cases of the transformed beta II distribution. A fast random generator for the Burr and the Pareto II distribution is implemented in Runuran as well as the density. EnvStats and LaplacesDemon provides d, p, q, r functions for Pareto I distribution. extremefit provides the Burr, the Pareto II, mixture of Pareto I distributions and a composite distribution of two Pareto I distributions. lmomco, evd, fExtremes, extraDistr, QRM, Renext, revdbayes, FAdist, LaplacesDemon, TLMoments qrmtools and evir packages implement the Generalized Pareto Distribution (from Extreme Value Theory), which is depending the shape parameter’s value a Pareto II distribution, a shifted exponential distribution or a generalized beta I distribution. ParetoPosStable implements the Pareto positive stable distribution. The extended Pareto distribution is implemented in RTDE and the shifted truncated (to unit interval) Pareto is implemented in mbbefd. ReIns provides Burr, extended Pareto, generalized Pareto, Pareto 1 distributions and their truncated version. CaDENCE provides the Pareto 2 and the zero-inflated Pareto 2 distribution. Pareto provides the Pareto 1, piecewise Pareto and the generalized Pareto (from actuarial theory).
Distribution name | Packages | Functions | Distribution suffix |
Pareto I | VGAM | d, p, q, r | paretoI |
Pareto I | actuar | d, p, q, r, m, lev | pareto1 |
Pareto I | EnvStats | d, p, q, r | pareto |
Pareto I | extraDistr | d, p, q, r | pareto |
Pareto I | ReIns | d, p, q, r | pareto |
Pareto I | LaplacesDemon | d, p, q, r | pareto |
Pareto I | distributionsrd | d, p, q, r | pareto |
Pareto I | Pareto | d, p, q, r | Pareto |
Trunc. Pareto I | ReIns | d, p, q, r | tpareto |
Pareto II | VGAM | d, p, q, r | paretoII |
Pareto II | actuar | d, p, q, r, m, lev | pareto, pareto2 |
Pareto II | Runuran | d, r | pareto |
Pareto II | extraDistr | d, p, q, h | lomax |
Pareto II | extremefit | d, p, q, h | pareto |
Pareto II | Renext | d, p, q, r | lomax |
Pareto II | rmutil | d, p, q, r | pareto |
Pareto II | CaDENCE | d, p, q, r | pareto2 |
zero-inflated Pareto II | CaDENCE | d, p, q, r | bpareto2 |
Pareto III | VGAM | d, p, q, r | paretoIII |
Pareto III | actuar | d, p, q, r | pareto3 |
Pareto IV | VGAM | d, p, q, r | paretoIV |
Pareto IV | actuar | d, p, q, r | pareto4 |
Inverse Pareto | actuar | d, p, q, r, m, lev | invpareto |
Inverse Pareto | distributionsrd | d, p, q, r, m, lev | invpareto |
Extended Pareto | RTDE | d, p, q, r | EPD |
Extended Pareto | ReIns | d, p, q, r | epd |
Shift. trunc. Pareto | mbbefd | d, p, q, r, m, ec | stpareto |
Gen. Pareto (actuarial) | actuar | d, p, q, r, m, lev | genpareto |
Gen. Pareto (actuarial) | Pareto | d, p, q, r | GenPareto |
Gen. Pareto (EVT) | lmomco | d, p, q, r | gpa |
Gen. Pareto (EVT) | evd | d, p, q, r | gpd |
Gen. Pareto (EVT) | fExtremes | d, p, q, r | gpd |
Gen. Pareto (EVT) | evir | d, p, q, r | gpd |
Gen. Pareto (EVT) | extraDistr | d, p, q, r | gpd |
Gen. Pareto (EVT) | QRM | d, p, q, r | GPD |
Gen. Pareto (EVT) | ReIns | d, p, q, r | gpd |
Gen. Pareto (EVT) | LaplacesDemon | d, r | gpd |
Gen. Pareto (EVT) | TLMoments | d, p, q, r | gpd |
Trunc. Gen. Pareto (EVT) | ReIns | d, p, q, r | tgpd |
Gen. Pareto (EVT) | revdbayes | d, p, q, r | gp |
Gen. Pareto (EVT) | Renext | d, p, q, r | GPD |
Gen. Pareto (EVT) | qrmtools | d, p, q, r | GPD |
Gen. Pareto (EVT) | ROOPSD | d, p, q, r | gpd |
Feller-Pareto | actuar | d, p, q, r, m, lev | fpareto |
Burr | actuar | d, p, q, r, m, lev | burr |
Burr | extremefit | d, p, q, r | burr |
Burr | ReIns | d, p, q, r | burr |
Burr | rmutil | d, p, q, r | burr |
Trunc. Burr | ReIns | d, p, q, r | tburr |
Inverse Burr | actuar | d, p, q, r, m, lev | invburr |
Student distribution and its extensions: Base R provides the d, p, q, r functions for Student and non central Student distribution (see above). extraDistr and LaplacesDemon provides the Student distribution with location and scale parameters. LaplacesDemon provides d, p, q, r functions for the Half-Student distribution. sadists implements Gram Charlier, Edgeworth and Cornish-Fisher approximations for doubly non central Student distribution for computing d, p, q, r functions. The skewed Student distribution is provided in skewt, sn and gamlss.dist packages. The generalized skew distribution is provided in sgt. d, p, q, r functions for the generalized t-distribution can be found in gamlss.dist. fBasics provides d, p, q, r functions for the skew and the generalized hyperbolic t-distribution. The L-moments of the Student t (3-parameter) are provided in lmomco. crch provides d, p, q, r functions for the truncated student distribution.
Distribution name | Packages | Functions | Distribution suffix |
Student | stats | d, p, q, r | t |
Student with loc. and scal. | extraDistr | d, p, q, r | lst |
Student with loc. and scal. | LaplacesDemon | d, p, q, r | st |
Doubly non central St. | sadists | d, p, q, r | dnt |
Skew Student | skewt | d, p, q, r | skt |
Skew Student | sn | d, p, q, r | st |
Skew St. Type 1-5 | gamlss.dist | d, p, q, r | ST1, ST2, ST3, ST4, ST5 |
Gen. Student | gamlss.dist | d, p, q, r | GT |
Gen. Hyp. Student | fBasics | d, p, q, r | ght |
Skew Gen. Student | sgt | d, p, q, r | sgt |
First-passage time of a Wiener process: WienR provides d, p functions of the first-passage time of a diffusion model.
Matrix normal distribution: MBSP (r) provides a random generator using a Cholesky decomposition; matrixsampling (r) provides a random generator using a spectral decomposition; LaplacesDemon and mniw (d, r); matrixNormal (d, p, r) collects these forms in one place and allows users to be flexible in simulating random variates (Cholesky, spectral, SVD).
rexp
) or from a multivariate normal distribution for large sparse matrices: typically for sparse covariance matrices.Zellner distribution: provided in LaplacesDemon.
mean()
, sd()
, var()
functions to compute the mean, standard deviation and variance, respectively.set.seed
and the kind of RNG can be specified using RNGkind
. The default RNG is the Mersenne-Twister algorithm. Other generators include Wichmann-Hill, Marsaglia-Multicarry, Super-Duper, Knuth-TAOCP, Knuth-TAOCP-2002, as well as user-supplied RNGs. For normal random numbers, the following algorithms are available: Kinderman-Ramage, Ahrens-Dieter, Box-Muller, Inversion (default). In addition to the tools above, setRNG provides an easy way to set, retain information about the setting, and reset the RNG.density()
), (2) the empirical cumulative distribution function (see ecdf()
), (3) the empirical quantile (see quantile()
) and (4) random sampling with or without replacement (see sample()
). distributionsrd provides d, p, q, r user-friendly functions for the empirical distributions as well as moments. mded provides a function for measuring the difference between two independent or non-independent empirical distributions and returning a significance level of the difference. MEPDF provides functions to compute and visualize empirical density functions for multivariate data.random()
, pdf()
, cdf()
and quantile()
provide replacements for base R’s r/d/p/q
style functions. distributional also provides tools to create and to manipulate probability distributions using S3, with cdf()
, density()
, hdr()
, mean()
, median()
, quantile()
,...fitdistr
function for parameter estimations. fitdistrplus greatly enlarges fitdistr
and enhances the tools to fit a user-supplied probability distribution. OneStep is based upon fitdistrplus to provide one-step estimation procedures. EnvStats, fitteR, ExtDist also provide tools to fit and select a set of probability distributions. flexsurv and msm provides a quantile function for a generic distribution based on numerical computation based on a dichotomic search.