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Univariate Discrete Distributions

Compute, fit, and generate samples from integer-valued distributions

A univariate discrete distribution is a probability distribution that contains a single random variable. This variable can assume only a finite, or countably infinite, number of values. For example, in a Bernoulli distribution, the random variable X can assume only the value 0 or 1.

Statistics and Machine Learning Toolbox™ offers several ways to work with univariate discrete distributions:

  • Create a distribution object and use distribution object functions.

  • Use distribution-specific functions with specified distribution parameters.

  • Use the generic distribution functions with the specified distribution name and corresponding parameters.

For more information, see Working with Probability Distributions.

Apps

Distribution FitterFit probability distributions to data

Tools

Probability Distribution Function ToolInteractive density and distribution plots
randtoolInteractive random number generation

Functions

expand all

cdfCumulative distribution function
icdfInverse cumulative distribution function
mleMaximum likelihood estimates
pdfProbability density function
randomRandom numbers
makedistCreate probability distribution object
fitdistFit probability distribution object to data
cdfCumulative distribution function
gatherGather properties of Statistics and Machine Learning Toolbox object from GPU
icdfInverse cumulative distribution function
iqrInterquartile range of probability distribution
meanMean of probability distribution
medianMedian of probability distribution
negloglikNegative loglikelihood of probability distribution
paramciConfidence intervals for probability distribution parameters
pdfProbability density function
plotPlot probability distribution object (Since R2022b)
proflikProfile likelihood function for probability distribution
qqplotQuantile-quantile plot
randomRandom numbers
stdStandard deviation of probability distribution
truncateTruncate probability distribution object
varVariance of probability distribution
binocdfBinomial cumulative distribution function
binopdfBinomial probability density function
binoinvBinomial inverse cumulative distribution function
binostatBinomial mean and variance
binofitBinomial parameter estimates
binorndRandom numbers from binomial distribution
ecdfEmpirical cumulative distribution function
ecdfhistHistogram based on empirical cumulative distribution function
geocdfGeometric cumulative distribution function
geopdfGeometric probability density function
geoinvGeometric inverse cumulative distribution function
geostatGeometric mean and variance
georndGeometric random numbers
hygecdfHypergeometric cumulative distribution function
hygepdfHypergeometric probability density function
hygeinvHypergeometric inverse cumulative distribution function
hygestatHypergeometric mean and variance
hygerndHypergeometric random numbers
nbincdfNegative binomial cumulative distribution function
nbinpdfNegative binomial probability density function
nbininvNegative binomial inverse cumulative distribution function
nbinstatNegative binomial mean and variance
nbinfitNegative binomial parameter estimates
nbinrndNegative binomial random numbers
poisscdfPoisson cumulative distribution function
poisspdfPoisson probability density function
poissinvPoisson inverse cumulative distribution function
poisstatPoisson mean and variance
poissfitPoisson parameter estimates
poissrnd Random numbers from Poisson distribution
unidcdfDiscrete uniform cumulative distribution function
unidpdfDiscrete uniform probability density function
unidinvDiscrete uniform inverse cumulative distribution function
unidstatDiscrete uniform mean and variance
unidrnd Random numbers from discrete uniform distribution

Objects

BinomialDistributionBinomial probability distribution object
EmpiricalDistributionEmpirical probability distribution object (Since R2025a)
NegativeBinomialDistributionNegative binomial distribution object
PoissonDistributionPoisson probability distribution object

Topics

  • Nonparametric and Empirical Probability Distributions

    Estimate a probability density function or a cumulative distribution function from sample data.

  • Bernoulli Distribution

    The Bernoulli distribution is a discrete probability distribution with only two possible values for the random variable.

  • Binomial Distribution

    The binomial distribution models the total number of successes in repeated trials from an infinite population under certain conditions.

  • Empirical Distribution

    The empirical distribution is a nonparametric estimate of the cumulative distribution function (cdf) for a sample.

  • Geometric Distribution

    The geometric distribution models the number of failures before one success in a series of independent trials, where each trial results in either success or failure, and the probability of success in any individual trial is constant.

  • Hypergeometric Distribution

    The hypergeometric distribution models the total number of successes in a fixed-size sample drawn without replacement from a finite population.

  • Multinomial Probability Distribution Objects

    This example shows how to generate random numbers, compute and plot the pdf, and compute descriptive statistics of a multinomial distribution using probability distribution objects.

  • Multinomial Probability Distribution Functions

    This example shows how to generate random numbers and compute and plot the pdf of a multinomial distribution using probability distribution functions.

  • Negative Binomial Distribution

    The negative binomial distribution models the number of failures before a specified number of successes is reached in a series of independent, identical trials.

  • Poisson Distribution

    The Poisson distribution is appropriate for applications that involve counting the number of times a random event occurs in a given amount of time, distance, area, and so on.

  • Uniform Distribution (Discrete)

    The discrete uniform distribution is a simple distribution that puts equal weight on the integers from one to N.

  • Maximum Likelihood Estimation

    The mle function computes maximum likelihood estimates (MLEs) for a distribution specified by its name and for a custom distribution specified by its probability density function (pdf), log pdf, or negative log likelihood function.

  • Negative Loglikelihood Functions

    Find maximum likelihood estimates using negative loglikelihood functions.