# DExp-class

From distr v2.6
0th

Percentile

##### Class "DExp"

The double exponential or Laplace distribution with rate $\lambda$ has density $$f(x) = \frac{1}{2}\lambda {e}^{- \lambda |x|}$$

C.f. Exp-class, rexp

Keywords
distribution
##### 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.

Exp-class ExpParameter-class AbscontDistribution-class Reals-class rexp

##### Aliases
• DExp-class
• DExp
• Laplace
• DoubleExponential
• initialize,DExp-method
##### Examples
D <- DExp(rate = 1) # D is a Laplace distribution with rate = 1.
r(D)(1) # one random number generated from this distribution, e.g. 0.4190765
d(D)(1) # Density of this distribution is 0.1839397 for x = 1.
p(D)(1) # Probability that x < 1 is 0.8160603.
q(D)(.1) # Probability that x < -1.609438 is 0.1.
rate(D) # rate of this distribution is 1.
rate(D) <- 2 # rate of this distribution is now 2.
3*D ###  still a DExp -distribution

Documentation reproduced from package distr, version 2.6, License: LGPL-3

### Community examples

Looks like there are no examples yet.