R: Class "Geom"

Geom-class {distr} | R Documentation

## Class "Geom"

### Description

The geometric distribution with `prob` = p has density

p(x) = p (1-p)^x

for x = 0, 1, 2, ...

C.f. `rgeom`

### Objects from the Class

Objects can be created by calls of the form `Geom(prob)`. This object is a geometric distribution.

### Slots

`img`

  Object of class `"Naturals"`: The space of the image of this distribution has got dimension 1 and the name "Natural Space".

`param`

  Object of class `"NbinomParameter"`: the parameter of this distribution (prob), declared at its instantiation (size=1)

`r`

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

`d`

  Object of class `"function"`: density function (calls function dgeom)

`p`

  Object of class `"function"`: cumulative function (calls function pgeom)

`q`

  Object of class `"function"`: inverse of the cumulative function (calls function qgeom). The quantile is defined as the smallest value x such that F(x) ≥ p, where F is the distribution function.

`support`

  Object of class `"numeric"`: a (sorted) vector containing the support of the discrete density function

`.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 `"DiscreteDistribution"`, directly.
Class `"Nbinom"`, directly.
Class `"UnivariateDistribution"`, by class `"DiscreteDistribution"`.
Class `"Distribution"`, by class `"DiscreteDistribution"`.

### Contains-Relations

By means of a `contains` argument in the class declaration, R “knows” that a distribution object `obj` of class `"Geom"` also is a negative Binomial distribution with parameters `size = 1, prob = prob(obj)`

### Methods

initialize

  `signature(.Object = "Geom")`: initialize method

prob

  `signature(object = "Geom")`: returns the slot prob of the parameter of the distribution

prob<-

  `signature(object = "Geom")`: modifies the slot prob of the parameter of the distribution

### Note

Working with a computer, we use a finite interval as support which carries at least mass `1-getdistrOption("TruncQuantile")`.

### Author(s)

Thomas Stabla statho3@web.de,
Florian Camphausen fcampi@gmx.de,
Peter Ruckdeschel peter.ruckdeschel@uni-oldenburg.de,
Matthias Kohl Matthias.Kohl@stamats.de

### See Also

`Nbinom-class` `GeomParameter-class` `DiscreteDistribution-class` `Naturals-class` `rgeom`

### Examples

    G <- Geom(prob = 0.5) # G is a geometric distribution with prob = 0.5.
    r(G)(1) # one random number generated from this distribution, e.g. 0
    d(G)(1) # Density of this distribution is 0.25 for x = 1.
    p(G)(1) # Probability that x<1 is 0.75.
    q(G)(.1) # x = 0 is the smallest value x such that p(G)(x) >= 0.1.
    ## in RStudio or Jupyter IRKernel, use q.l(.)(.) instead of q(.)(.)
    prob(G) # prob of this distribution is 0.5.
    prob(G) <- 0.6 # prob of this distribution is now 0.6.
    as(G,"Nbinom")
    G+G+G

[Package distr version 2.8.0 Index]