zinb {bizicount}  R Documentation 
These functions are used to evaluate the zeroinflated negative binomial distribution's probability mass function (PMF), cumulative distribution function (CDF), and quantile function (inverse CDF), as well as generate random realizations from the ZINB distribution.
dzinb(
x,
size,
psi,
mu = NULL,
prob = NULL,
lower.tail = TRUE,
log = FALSE,
recycle = FALSE
)
pzinb(
q,
size,
psi,
mu = NULL,
prob = NULL,
lower.tail = TRUE,
log.p = FALSE,
recycle = FALSE
)
qzinb(
p,
size,
psi,
mu = NULL,
prob = NULL,
lower.tail = TRUE,
log.p = FALSE,
recycle = FALSE
)
rzinb(n, size, psi, mu = NULL, prob = NULL, recycle = FALSE)
x, q 
Vector of quantiles at which to evaluate the PMF and CDF, respectively. Should be nonnegative integers. 
size 
The inverse dispersion parameter, or number of successful trials,
both for the negative binomial portion of the ZINB mixture distribution.
See 
psi 
Vector of zeroinflation probabilities. 
mu 
Vector of means for the count portion of the zeroinflated negative
binomial distribution. Only one of 
prob 
The probability of success on each trial in the negative binomial portion of the mixture distribution. Only one of 
lower.tail 
Logical indicating whether probabilities should be

log, log.p 
Logical indicating whether probabilities should be returned
on log scale (for 
recycle 
Logical indicating whether to permit arbitrary recycling of arguments with unequal length. See 'Details' and 'Examples.' 
p 
Vector of probabilities at which to evaluate the quantile function. 
n 
Number of realizations to generate from the distribution 
dzinb
returns the mass function evaluated at x
,
pzinb
returns the CDF evaluated at q
, qzinb
returns the quantile
function evaluated at p
, and rzinb
returns random realizations with the
specified parameters.
John Niehaus
Lambert, Diane. "Zeroinflated Poisson regression, with an application to defects in manufacturing." Technometrics 34.1 (1992): 114.
# zeroinflated negative binomial examples
# two unique lengthed arguments, one is length 1 though. No error.
dzinb(4, size=.25, mu= c(1,2,3), psi=c(.2, .1, .15))
# two unique lengthed arguments, one of them is not length 1
# error
## Not run:
dzinb(5, size=c(.25, .3), mu= c(1,2,3), psi=c(.2, .1, .15))
## End(Not run)
# two unique lengthed arguments, one of them is not length 1, set
# recycle = T, no error but can give innacurate results.
dzinb(5, size=c(.25, .3), mu= c(1,2,3), psi=c(.2, .1, .15), recycle=TRUE)