R: Collection of functions for logistic detection functions
is.linear.logistic
R Documentation
Collection of functions for logistic detection functions
Description
These functions are used to test whether a logistic detection function is a
linear function of distance (is.linear.logistic) or is constant
(varies by distance but no other covariates) is.logistic.constant).
Based on these tests, the most appropriate manner for integrating the
detection function with respect to distance is chosen. The integrals are
needed to estimate the average detection probability for a given set of
covariates.
Usage
is.linear.logistic(xmat, g0model, zdim, width)
Arguments
xmat
data matrix
g0model
logit model
zdim
number of columns in design matrix
width
transect width
Details
If the logit is linear in distance then the integral can be computed
analytically. If the logit is constant or only varies by distance then only
one integral needs to be computed rather than an integral for each
observation.
Value
Logical TRUE if condition holds and FALSE otherwise