qualap: Quantile Function of the Laplace Distribution
Description
This function computes the quantiles of the Laplace distribution given parameters ($\xi$ and $\alpha$) of the distribution computed by parlap. The quantile function of the distribution is
$$x(F) = \xi + \alpha\times\log(2F) \mbox{ for } F \le 0.5\mbox{, and}$$
$$x(F) = \xi - \alpha\times\log(2(1-F)) \mbox{ for } F > 0.5\mbox{,}$$
where $x(F)$ is the quantile for nonexceedance probability $F$,
$\xi$ is a location parameter and $\alpha$ is a scale parameter.
A logical controlling whether the parameters and checked for validity. Overriding of this check might be extremely important and needed for use of the distribution quantile function in the context of TL-moments with nonzero trimming.
Value
Quantile value for for nonexceedance probability $F$.
References
Hosking, J.R.M., 1986, The theory of probability weighted moments: IBM Research Report RC12210, T.J. Watson Research Center, Yorktown Heights, New York.