Computes abundance estimates at specified parameter values using Horvitz-Thompson-like estimator

Computes abundance at specified values of parameters for numerical computation of first derivative with respect to parameters in detection function. An internal function called by DeltaMethod which is invoked by dht.se

Usage

dht.deriv(par, model, obs, samples, options = list())

Arguments

par: detection function parameter values
model: ddf model object
obs: observations table
samples: samples table
options: list of options as specified in dht

Value

vector of abundance estimates at values of parameters specified in par

Note

Internal function; not intended to be called by user

Author

Jeff Laake