ecospat.permut.glm {ecospat} R Documentation

## GLM Permutation Function

### Description

A permutation function to get p-values on GLM coefficients and deviance.

### Usage

ecospat.permut.glm (glm.obj, nperm, verbose = FALSE)

### Arguments

 glm.obj Any calibrated GLM or GAM object with a binomial error distribution. nperm The number of permutations in the randomization process. verbose Boolean indicating whether to print progress output during calculation. Default is FALSE.

### Details

Rows of the response variable are permuted and a new GLM is calibrated as well as deviance, adjusted deviance and coefficients are calculated. These random parameters are compared to the true parameters in order to derive p-values.

### Value

Return p-values that are how the true parameters of the original model deviate from the disribution of the random parameters. A p-value of zero means that the true parameter is completely outside the random distribution.

### Author(s)

Christophe Randin christophe.randin@unibas.ch, Antoine Guisan antoine.guisan@unil.ch and Trevor Hastie

### References

Hastie, T., R. Tibshirani and J. Friedman. 2001. Elements of Statistical Learning; Data Mining, Inference, and Prediction, Springer-Verlag, New York.

Legendre, P. and L. Legendre. 1998. Numerical Ecology, 2nd English edition. Elsevier Science BV, Amsterdam.

### Examples



if(require("rms",quietly=TRUE)){
data('ecospat.testData')

# data for Soldanella alpina