Exponential: The Exponential Distribution

In nimble: MCMC, Particle Filtering, and Programmable Hierarchical Modeling

The Exponential Distribution

Description

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

Usage

dexp_nimble(x, rate = 1/scale, scale = 1, log = FALSE)

rexp_nimble(n = 1, rate = 1/scale, scale = 1)

pexp_nimble(q, rate = 1/scale, scale = 1, lower.tail = TRUE, log.p = FALSE)

qexp_nimble(p, rate = 1/scale, scale = 1, lower.tail = TRUE, log.p = FALSE)

Arguments

x	vector of values.
rate	vector of rate values.
scale	vector of scale values.
log	logical; if TRUE, probability density is returned on the log scale.
n	number of observations.
q	vector of quantiles.
lower.tail	logical; if TRUE (default) probabilities are P[X \le x]; otherwise, P[X > x].
log.p	logical; if TRUE, probabilities p are given by user as log(p).
p	vector of probabilities.

Details

NIMBLE's exponential distribution functions use Rmath's functions under the hood, but are parameterized to take both rate and scale and to use 'rate' as the core parameterization in C, unlike Rmath, which uses 'scale'. See Gelman et al., Appendix A or the BUGS manual for mathematical details.

Value

dexp_nimble gives the density, pexp_nimble gives the distribution function, qexp_nimble gives the quantile function, and rexp_nimble generates random deviates.

Author(s)

Christopher Paciorek

References

Gelman, A., Carlin, J.B., Stern, H.S., and Rubin, D.B. (2004) Bayesian Data Analysis, 2nd ed. Chapman and Hall/CRC.

See Also

Distributions for other standard distributions

Examples

x <- rexp_nimble(50, scale = 3)
dexp_nimble(x, scale = 3)

nimble documentation built on Sept. 11, 2024, 7:10 p.m.