Title Poisson Lognormal and Bivariate Poisson Lognormal Distribution

Package 'poilog' Title Poisson Lognormal and Bivariate Poisson Lognormal Distribution

February 15, 2013 Type Package Title Poisson lognormal and bivariate Poisson lognormal distribution Version 0.4 Date 2008-04-29 Author Vidar Grøtan and Steinar Engen Maintainer Vidar Grøtan Description Functions for obtaining the density, random deviates and maximum likelihood estimates of the Poisson lognormal distribution and the bivariate Poisson lognormal distribu...

Correlation in The Bivariate Poisson Regression Model

We consider a bivariate Poisson model that is based on the lognormal heterogeneity model. Two recent applications have used this model. We suggest that the correlation estimated in their model frameworks is an ambiguous measure of the correlation of the variables of interest, and may substantially overstate it. We conclude with a detailed application of the proposed method using the data employ...

Analyzing spatial structure of communities using the two-dimensional poisson lognormal species abundance model.

The joint spatial and temporal fluctuations in the community structure of tropical butterflies are analyzed by fitting the bivariate Poisson lognormal distribution to a large number of observations in space and time. By applying multivariate dependent diffusions for describing the fluctuations in the abundances, the environmental variance is estimated to be very large and so is the strength of ...

Characteristics Based Heuristics to Select a Logical Distribution between the Poisson-Gamma and the Poisson-Lognormal for Crash Data Modeling

Poisson-Gamma and Poisson-Lognormal models for the characterisation of within- batch and between-batch variability in microbial counts in foods

In modelling risk management strategies (i.e., within-lot batch testing, statistical process control), two basic assumptions have been normally made: that the true concentration of microorganisms are log-normally distributed within a batch, and that the variance of the samples is the same for a little or highly contaminated lot. These assumptions were evaluated by characterising the between-bat...