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The Negative Binomial Distribution
Syntax
dnbinom(x, n, p)
pnbinom(q, n, p)
qnbinom(prob, n, p)
rnbinom(nobs, n, p)
Description
These functions provide information about the negative binomial
distribution with parameters n
and p
. dnbinom
gives the density, pnbinom
gives the distribution function
qnbinom
gives the quantile function and rnbinom
generates
random deviates.
The negative binomial distribution has density
p(x) = Choose(x+n-1,x) p^n (1-p)^x
((Equations will(?) come with HTML 3.x ))
for x = 0, 1, 2, ...
See Also
dbinom
for the binomial and dpoisson
for the
Poisson distribution.
Examples
x <- 0:11
dnbinom(x, n = 1, p = 1/2) * 2^(1 + x) # == 1
126 / dnbinom(0:8, n = 2, p = 1/2) #- theoretically integer
## Cumulative ('p') = Sum of discrete prob.s ('d'); Relative error
summary(1 - cumsum(dnbinom(x, n=2, p= 1/2)) / pnbinom(x, n=2, p= 1/2))