# Double-Exponential: The Double Exponential (Laplace) Distribution In nimble: MCMC, Particle Filtering, and Programmable Hierarchical Modeling

 Double-Exponential R Documentation

## The Double Exponential (Laplace) Distribution

### Description

Density, distribution function, quantile function and random generation for the double exponential distribution, allowing non-zero location, `mu`, and non-unit scale, `sigma`, or non-unit rate, `tau`

### Usage

``````ddexp(x, location = 0, scale = 1, rate = 1/scale, log = FALSE)

rdexp(n, location = 0, scale = 1, rate = 1/scale)

pdexp(
q,
location = 0,
scale = 1,
rate = 1/scale,
lower.tail = TRUE,
log.p = FALSE
)

qdexp(
p,
location = 0,
scale = 1,
rate = 1/scale,
lower.tail = TRUE,
log.p = FALSE
)
``````

### Arguments

 `x` vector of values. `location` vector of location values. `scale` vector of scale values. `rate` vector of inverse 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

See Gelman et al., Appendix A or the BUGS manual for mathematical details.

### Value

`ddexp` gives the density, `pdexp` gives the distribution function, `qdexp` gives the quantile function, and `rdexp` 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.

``````x <- rdexp(50, location = 2, scale = 1)