DLMtool (version 3.2)

getmov: Optimization function to find a movement model that matches user specified movement characteristics.

Description

The user specifies the probability of staying in the same area and spatial heterogeneity (both in the unfished state).

Usage

getmov(x,Prob_staying,Frac_area_1)

Arguments

x

A position in vectors Prob_staying and Frac_area_1

Prob_staying

User specified probability that individuals in area 1 remain in that area (unfished conditions)

Frac_area_1

User specified fraction of individuals found in area 1 (unfished conditions)

Value

A markov movement matrix

Details

This is paired with movfit to find the correct movement model.

Examples

Prob_staying<-0.8 # probability  that individuals remain in area 1 between time-steps
Frac_area_1<-0.35 # the fraction of the stock found in area 1 under equilibrium conditions
markovmat<-getmov(1,Prob_staying, Frac_area_1)
vec<-c(0.5,0.5) # initial guess at equilibrium distribution (2 areas)
for(i in 1:300)vec<-apply(vec*markovmat,2,sum) # numerical approximation to stable distribution
c(markovmat[1,1],vec[1]) # pretty close right?