# (INTRO.DISTR)

##### DISTR

The aim of this package is to provide a conceptual treatment of random variables (r.v.'s) by means of S4 classes.
A mother class `Distribution`

is introduced with slots for a parameter and ---most important---
for the four constitutive methods `r`

, `d`

, `p`

, and `q`

for simulation respectively for evaluation of
density / c.d.f. and quantile function of the corresponding distribution. All distributions of the `r`

-, `d`

-, `p`

-, and `q`

-functions exist (like normal, Poisson, etc.)
are implemented as subclasses of either `AbscontDistribution`

or `DiscreteDistribution`

,
which themselves are again subclasses of `Distribution`

.
This approach seems very appealing to us from a conceptual viewpoint:

*Just pass an object of some derived distribution class to a generic function as argument
and let the dispatching mechanism decide what to do on run-time.*

As an example, we may automatically generate new objects of these classes with corresponding
`r`

, `d`

, `p`

, and `q`

-slots for the laws of r.v.'s under standard mathematical
univariate transformations and under convolution of independent r.v.'s. For `Distribution`

objects `X`

and `Y`

expressions like
`3*X+sin(exp(-Y/4+3))`

have their natural interpretation as corresponding image distributions.

Additionally, we also provide classes for a standardized treatment of simulations (also under contaminations) and evaluations of statistical procedures on such simulations. A somewhat longer and more detailed manual can be obtained under

##### center

S4 Classes for Distributions

##### synopsis

##### Usage

library("distr")

*Documentation reproduced from package distr, version 1.5, License: GPL (version 2 or later)*