com.compute.z: Compute COM-Poisson Normalizing Constant

In compoisson: Conway-Maxwell-Poisson Distribution

Description

Computes the normalizing constant in the COM-Poisson model for given values of the parameters.

Usage

	com.compute.z(lambda, nu, log.error = 0.001)
	com.compute.log.z(lambda, nu, log.error = 0.001)

Arguments

lambda	Lambda value in COM-Poisson distribution
nu	Nu value in COM-Poisson distribution
log.error	Precision in the log of the normalizing constant

Details

com.compute.z computes the COM-Poisson normalizing constant

z = Sum (lambda^j)/(j!^nu)

to the specified precision. If no precision is specified, then the package default is used.

com.compute.log.z is equivalent to log(com.compute.z(lambda, nu)) but provudes additional precision.

Value

The normalizing constant as a real number with specified precision.

Author(s)

Jeffrey Dunn

References

Shmueli, G., Minka, T. P., Kadane, J. B., Borle, S. and Boatwright, P., “A useful distribution for fitting discrete data: Revival of the Conway-Maxwell-Poisson distribution,” J. Royal Statist. Soc., v54, pp. 127-142, 2005.

See Also

com.fit

Examples

	data(insurance);
	fit = com.fit(Lemaire);
	z = com.compute.z(fit$lambda, fit$nu);

Example output

Loading required package: MASS

compoisson documentation built on May 1, 2019, 11:17 p.m.