SimData: Simulated movement data

In ICvectorfields: Vector Fields from Spatial Time Series of Population Abundance

Simulated movement data

Description

Data based on a partial differential equation were simulated using the ReacTran R package (see details).

Usage

data(SimData)

Format

A data-frame with 40804 rows and 8 columns.

xcoord

in arbitrary units

ycoord

in arbitrary units

t1

concentration in arbitrary units at t = 1

t2

concentration in arbitrary units at t = 2

t3

concentration in arbitrary units at t = 3

t4

concentration in arbitrary units at t = 4

t5

concentration in arbitrary units at t = 5

t6

concentration in arbitrary units at t = 6

Details

The simulation algorithm uses a finite differencing scheme with backwards differencing. The model used for simulation is a reaction diffusion-advection equation in which the advection term is variable in space but diffusion and reactions are constant in space see convection-diffusion equation for an example.

The parameters used in the general partial differntial equation in the link above are

D = 0.01 per squared spatial unit

R = 0.5 per unit time

v (advection is variable in space): in the upper left quadrant of the square domain v = (0.2, 0); in the upper right quadrant v = (0, -0.2); in the lower right quadrant v = (-0.2, 0); in the lower right quadrant v = (0, 0.2). Obviously v is discontinous at the quadrant boundaries, which causes some interesting model behaviour that is limited by considering only the first six time steps such that the bulk of the concentration in each quadrant does not cross a quadrant boundary.

The intial condition at time = 0 is a concentration of one unit per arbitrary unit of volume in the central cell of each quadrant.

External boundary conditions are zero-gradient (reflecting).

The data are formatted such that they can easily be converted to a raster stack using ICvectorfields::RastStackData(SimData).

ICvectorfields documentation built on March 18, 2022, 7:34 p.m.