tscount (version 1.3.0)

countdistr: Count Data Distributions

Description

Density, distribution function, quantile function, random generation, standard deviation and Anscombe residuals for some count data distributions. These auxiliary functions are used by several functions of the tscount package.

Usage

ddistr(x, meanvalue, distr=c("poisson", "nbinom"), distrcoefs, ...)
pdistr(q, meanvalue, distr=c("poisson", "nbinom"), distrcoefs, ...)
qdistr(p, meanvalue, distr=c("poisson", "nbinom"), distrcoefs, ...)
rdistr(n, meanvalue, distr=c("poisson", "nbinom"), distrcoefs)
sddistr(meanvalue, distr=c("poisson", "nbinom"), distrcoefs)
ardistr(response, meanvalue, distr=c("poisson", "nbinom"), distrcoefs)
checkdistr(distr=c("poisson", "nbinom"), distrcoefs)

Arguments

x

vector of (non-negative integer) quantiles.

q

vector of quantiles.

p

vector of probabilities.

n

positive integer value giving the number of random values to return.

response

vector of true observations for calculation of residuals.

meanvalue

non-negative numeric vector of means.

distr

character value giving the distribution. Possible values are currently "poisson" (the default) for the Poisson distribution and "nbinom" for the NegBinomial distribution.

distrcoefs

vector of additional distribution coefficients. For the Poisson distribution this argument can be omitted. For the negative binomial distribution it needs to be a vector of length one giving the value for the parameter size as specified in NegBinomial.

...

additional arguments logt, lower.tail or log.p to be passed to other functions (see Poisson or NegBinomial).

Details

Basically, these function are wrappers for specific functions for the respective distribution. The function ddistr gives the density of the specified distribution, pdistr the distribution function, qdistr the quantile function and rdistr generates random deviates from this distribution. These functions are a generalisation of the respective functions where distr is replaced by either pois or nbinom. The function sddistr returns the standard deviation of the specified distribution. The function ardistr calculates Anscombe residuals for given values of the response. The function checkdistr is for verification of the arguments distr and distrcoefs.

See Also

Poisson for the Poisson distribution and NegBinomial for the negative binomial distribution.

tsglm for fitting a more genereal GLM for time series of counts.