E Using R with distributions

In R, standard distributions have four associated functions:

Computing the probability function: All begin with p (such as pnorm() for the normal distribution).
Computing the distribution function: All begin with d(such as dnorm()).
Computing the quantile function: All begin with q (such as qnorm()).
Generating random numbers: All begin with r (such as rnorm()).

For example, for the normal distribution (denoted norm in R) the four functions above are called:

E.1 Univariate distributions

Common parameters:

Most distributions have other parameters also; check the help (e.g., ?punif).

	Probability	Distribution	Quantile	Random
Distribution	function	function	function	numbers
Discrete uniform				`sample()`
Binomial	`dbinom()`	`pbinom()`	`qbinom()`	`rbinom(n, )`
Poisson	`dpois()`	`ppois()`	`qpois()`	`rpois(n, )`
Geometric	`dgeom()`	`pgeom()`	`qgeom()`	`rgeom(n, )`
Negative binomial	`dnbinom()`	`pnbinom()`	`qnbinom()`	`rnbinom(n, )`
Continuous uniform	`dunif()`	`punif()`	`qunif()`	`runif(n, )`
Normal	`dnorm()`	`pnorm()`	`qnorm()`	`rnorm(n, )`
Exponential	`dexp()`	`pexp()`	`qexp()`	`rexp(n, )`
Gamma	`dgamma()`	`pgamma()`	`qgamma()`	`rgamma(n, )`
Log-normal	`dlnorm()`	`plnorm()`	`qlnorm()`	`rlnorm(n, )`
\(t\)	`dt()`	`pt()`	`qt()`	`rt(n, )`
\(\chi\)-squared	`dchisq()`	`pchisq()`	`qchisq()`	`rchisq(n, )`
\(F\)	`df()`	`pf()`	`qf()`	`rf(n, )`

The multinomial distribution:

The multivariate normal distribution: