get.Q: Create a precision matrix from a transition list and a set of...

In rwc: Random Walk Covariance Models

Create a precision matrix from a transition list and a set of log-conductance rates.

Description

Creates a precision matrix Q, with off diagonal entries equal to exp(b1*x_1ij + ... + bp*x_pij), where beta=(b1,b2,...,bp) is a vector of log-conductance values of the covariates x_kij. Each x_kij is equal to (x_ki+x_kj)/2.

Usage

get.Q(TL, beta)

Arguments

TL	A transition list from TL.from.stack
beta	A vector of log-conductance rates with length equal to the length of TL.

Value

A precision matrix, as a sparse matrix of class 'dgCMatrix', with dimension equal to n^2 by n^2, where n is the number of nodes in the raster stack used to compute TL.

Author(s)

Ephraim M. Hanks

References

Hanks and Hooten 2013. Circuit theory and model-based inference for landscape connectivity. Journal of the American Statistical Association. 108(501), 22-33.

Examples

int=raster(nrow=30,ncol=30)
values(int)=1
B.int=get.TL(int)
Q.int=get.Q(B.int,1)

rwc documentation built on April 4, 2025, 4:40 a.m.