migration: Construct a 'migration' Object.

In petrelharp/landsim: Simulate Populations on Landscapes

Description

This puts together the parameters necessary to specify a migration object, specifying the form of the dispersal and the total number of dispersers.

Usage

migration(kern, radius, sigma = 1, normalize = 1, n.weights = 1,
  do.M = FALSE, population, ...)

Arguments

kern	A function of scaled distance giving relative weights. (or, "gaussian", "cauchy")
radius	The maximum distance to migrate over.
sigma	A number that distances are scaled by before being passed to kern.
normalize	Total number of migrants per unit of input.
n.weights	Weights on the number of times to apply the smoother: the resulting operator is x -> (1-sum(n.weights)) * x + n.weights[1] * M x + n.weights[2] * M^2 x + ...
do.M	Precompute an explicit migration matrix?
population	A population; used in computing M.
...	Other parameters that are included verbatim in the output object.
from	Used in computing M.
to	Used in computing M.

Value

A migration S3 object (just a named list).

If kern is a migration object, can be used to add a migration matrix to it. See migration_matrix.

Since the memory usage of the migration matrix increases quadratically with the size of the radius, it can be useful to keep it small and instead apply the migration operator several times; this is achieved by setting n.weights to have weight at indices larger than 2.

petrelharp/landsim documentation built on May 25, 2019, 2:53 a.m.