# DExp-class: Class "DExp" In distr: Object Oriented Implementation of Distributions

## Description

The double exponential or Laplace distribution with rate λ has density

f(x) = 1/2 lambda e^(- lambda |x|)

C.f. Exp-class, rexp

## Objects from the Class

Objects can be created by calls of the form DExp(rate). This object is a double exponential (or Laplace) distribution.

## Slots

img

Object of class "Reals": The space of the image of this distribution has got dimension 1 and the name "Real Space".

param

Object of class "ExpParameter": the parameter of this distribution (rate), declared at its instantiation

r

Object of class "function": generates random numbers (calls function rexp)

d

Object of class "function": density function (calls function dexp)

p

Object of class "function": cumulative function (calls function pexp)

q

Object of class "function": inverse of the cumulative function (calls function qexp)

.withArith

logical: used internally to issue warnings as to interpretation of arithmetics

.withSim

logical: used internally to issue warnings as to accuracy

.logExact

logical: used internally to flag the case where there are explicit formulae for the log version of density, cdf, and quantile function

.lowerExact

logical: used internally to flag the case where there are explicit formulae for the lower tail version of cdf and quantile function

Symmetry

object of class "DistributionSymmetry"; used internally to avoid unnecessary calculations.

## Extends

Class "AbscontDistribution", directly.
Class "UnivariateDistribution", by class "AbscontDistribution". Class "Distribution", by class "AbscontDistribution".

## Methods

initialize

signature(.Object = "DExp"): initialize method

rate

signature(object = "DExp"): returns the slot rate of the parameter of the distribution

rate<-

signature(object = "DExp"): modifies the slot rate of the parameter of the distribution

*

signature(e1 = "DExp", e2 = "numeric"): For the Laplace distribution we use its closedness under scaling transformations.

## Author(s)

Peter Ruckdeschel [email protected]