# ncg: Computes the noncentral gamma functions: pdf, cdf, quantiles... In ncg: Computes the noncentral gamma function

## Description

Computes the noncentral gamma functions: pdf, cdf, quantiles and noncentrality parameter. This functions uses the mixture of incomplete gamma variable with Poisson weights.

## Details

given x: vector of positive quantiles; alpha > 0 noncentral gamma parameter; and delta: noncentrality parameter

dgammanc(x, alpha, delta) - computes the pdf of the noncetral gamma function
pgammanc(x, alpha, delta) - computes the cdf of the noncetral gamma function

given p: vector of cumulative probabilities and alpha>0 and delta >0

qgammanc(p, alpha, delta) - computes quantiles of the noncetral gamma function

given x: vector of positive quantiles; alpha > 0 noncentral gamma parameter; and 0 < p < 1.

deltagammanc(x, alpha, p) - computes the noncentrality parameter of the noncetral gamma function

## Author(s)

Daniel Furtado Ferreira and Izabela Regina Cardoso de Oliveira and Fernando Henrique Toledo

Maintainer: Daniel Furtado Ferreira <[email protected]>

## References

Oliveira, IRC; Ferreira, DF Computing the noncentral gamma distribution, its inverse and the noncentrality parameter. Computational Statistics. Submmited for publications. 2012.

## See Also

Package homepage: `<www.dex.ufla.br/~danielff/r_rsources.html>`

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12``` ```library(ncg) x <- c(2, 3, 2) alpha <- c(1.5, 1.1, 0.8) delta <- 2 pgammanc(x, alpha, delta) dgammanc(x, alpha, delta) p <- 0.30 delta <- deltagammanc(x, alpha, p) delta p <- c(0.80, 0.98, 0.24) delta <- 0.2 qgammanc(p, alpha, delta) ```

ncg documentation built on May 29, 2017, 2:08 p.m.