Exponential {base}R Documentation

The Exponential Distribution

Description

Density, distribution function, quantile function and random generation for the exponential distribution with rate rate (i.e., mean 1/rate).

Usage

dexp(x, rate = 1, log = FALSE)
pexp(q, rate = 1, lower.tail = TRUE, log.p = FALSE)
qexp(p, rate = 1, lower.tail = TRUE, log.p = FALSE)
rexp(n, rate = 1)

Arguments

x, q vector of quantiles.
p vector of probabilities.
n number of observations to generate.
rate vector of rates.
log, log.p logical; if TRUE, probabilities p are given as log(p).
lower.tail logical; if TRUE (default), probabilities are P[X <= x], otherwise, P[X > x].

Details

If rate is not specified, it assumes the default value of 1.

The exponential distribution with rate λ has density

f(x) = lambda e^(- lambda x)

for x >= 0.

Value

dexp gives the density, pexp gives the distribution function, qexp gives the quantile function, and rexp generates random deviates.

See Also

exp for the exponential function, dgamma for the gamma distribution and dweibull for the Weibull distribution, both of which generalize the exponential.

Examples

dexp(1) - exp(-1) #-> 0
r <- rexp(100)
all(abs(1 - dexp(1, r) / (r*exp(-r))) < 1e-14)

[Package Contents]