transect.intensity {DSpat}R Documentation

Compute expected and observed counts by distance within transect

Description

Computes the expected and observed counts for equally-spaced bins of perpendincular distance within each transect. Expected and observed counts are each a matrix with a row for each transect and a column for each distance bin.

Usage

transect.intensity(x, epsvu=NULL, obs.ppp, covariates, nclass=NULL, width)

Arguments

x dspat object
epsvu epsvu setting for fitted model; only uses epsvu[2] value for u
obs.ppp observation point process
covariates dataframe of covariates at quadrature points
nclass number of equally-spaced distance intervals within 0-width/2
width maximum full transect width over all transects

Details

The actual number of distance bins will only match nclass if it is selected such that nclass*epsvu[2] is an even multiple of width/2. The function dspat adjusts epsvu[2] such that it is an even multiple of width/2 and this function assumes that condition holds. Sometimes your choice of epsvu[2] will provide less than optimal choices for nclass and in some cases it can only choose a single bin. In these cases, select another value of epsvu[2] which is a multiple for width/2.

If nclass is not specified then it uses the default of ceiling(sqrt(n)) intervals.

Value

exp.counts matrix of expected counts in each distance bin (columns) for each transect (row)
obs.counts matrix of observed counts in each distance bin (columns) for each transect (row)

Author(s)

Jeff Laake


[Package DSpat version 0.1.0 Index]