Class "Nbinom"

The negative binomial distribution with size $= n$, by default $=1$, and prob $= p$, by default $=0.5$, has density $$d(x) = \frac{\Gamma(x+n)}{\Gamma(n) x!} p^n (1-p)^x$$ for $x = 0, 1, 2, \ldots$ This represents the number of failures which occur in a sequence of Bernoulli trials before a target number of successes is reached. C.f. rnbinom


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

Objects from the Class

Objects can be created by calls of the form Nbinom(prob, size). This object is a negative binomial distribution.


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


  • discrete distribution
  • lattice distribution
  • Negative Binomial distribution
  • S4 parameter class
  • generating function

See Also

NbinomParameter-class Geom-class DiscreteDistribution-class Naturals-class rnbinom

  • Nbinom-class
  • Nbinom
  • initialize,Nbinom-method
N <- Nbinom(prob = 0.5, size = 1) # N is a binomial distribution with prob=0.5 and size=1.
r(N)(1) # one random number generated from this distribution, e.g. 3
d(N)(1) # Density of this distribution is  0.25 for x=1.
p(N)(0.4) # Probability that x<0.4 is 0.5.
q(N)(.1) # x=0 is the smallest value x such that p(B)(x)>=0.1.
size(N) # size of this distribution is 1.
size(N) <- 2 # size of this distribution is now 2.
Documentation reproduced from package distr, version 2.0.6, License: LGPL-3

Community examples

Looks like there are no examples yet.