R: The Geometric Distribution

The Geometric Distribution

Usage

dgeom(x, prob)
pgeom(q, prob)
qgeom(p, prob)
rgeom(n, prob)

Arguments

`x,q`	vector of quantiles representing the number of failures in a sequence of Bernoulli trials before success occurs.
`p`	vector of probabilities.
`n`	number of observations to generate.
`prob`	probability of success in each trial.

Description

These functions provide information about the geometric distribution with parameter prob. dgeom gives the density, pgeom gives the distribution function, qgeom gives the quantile function, and rgeom generates random deviates.

Details

The geometric distribution with prob = p has density

p(x) = p (1-p)^x

for x = 0, 1, 2, ...

If an element of x is not integer, the result of pgeom is zero, with a warning.

Examples

pp <- sort(c((1:9)/10, 1 - .2^(2:8)))
print(qg <- qgeom(pp, prob = .2))
for(i in 1:2) print(qg <- qgeom(pgeom(qg, prob=.2), prob =.2))
Ni <- rgeom(20, prob = 1/4); table(factor(Ni, 0:max(Ni)))