speedGammaModel: Gamma Behavioural Model

In SWotherspoon/SGAT: Solar/Satellite Geolocation for Animal Tracking

Gamma Behavioural Model

Description

Movement model that assumes speeds are Gamma distributed

Usage

speedGammaModel(beta, dt)

Arguments

beta	parameters of the behavioural model.
dt	time intervals for speed calculation in hours.

Details

This function implements a movement model that assumes the speed of travel between locations is Gamma distributed, and for Estelle models, the change in bearing along the dog-leg path segments can be assumed Normally distributed with mean zero.

For Stella models, average speeds is calculated along great circle paths between primary locations (x). For Estelle, average speed is calculated along dog leg paths through the intermediate points (z), and the change in bearing at each intermediate point calculated.

If beta is a vector, then beta[1] and beta[2] specify the shape and rate of the Gamma distribution of speeds. If beta has three elements, then beta[3] specifies the standard deviation of the change in bearing (in degrees) along dog leg paths.

Alternately, these parameters can be specified individually for each track segment by passing beta as a matrix with one row for each segment.

Value

Functions to evaluate the contributions to the log posterior for the Estelle and Stella models.

See Also

satelliteModel, thresholdModel, groupedThresholdModel, curveModel.

SWotherspoon/SGAT documentation built on June 1, 2022, 10:49 p.m.