Skellam {VGAM} | R Documentation

## The Skellam Distribution

### Description

Density and random generation for the Skellam distribution.

### Usage

    dskellam(x, mu1, mu2, log=FALSE)
    rskellam(n, mu1, mu2)

### Arguments

`x` | vector of quantiles.
`n` | number of observations. Must be a positive integer of length 1.
`mu1, mu2` | See `skellam`
`log` | Logical; if TRUE, the logarithm is returned.

### Details

See `skellam`, the VGAM family function for estimating the parameters, for the formula of the probability density function and other details.

### Value

`dskellam` gives the density, and `rskellam` generates random deviates.

### Warning

Numerical problems may occur for data if mu1 and/or mu2 are large. The normal approximation for this case has not been implemented yet.

### Author(s)

T. W. Yee

### See Also

`skellam`, `dpois`.

### Examples

    ## Not run:
    mu1 = 1; mu2 = 2
    x = (-7):7
    plot(x, dskellam(x, mu1, mu2), type="h", las=1, col="blue",
         main=paste("Density of Skellam distribution with mu1=", mu1,
                    " and mu2=", mu2, sep=""))
    ## End(Not run)

[Package VGAM version 0.7-9 Index]