rast.grad: Creates gradient rasters from a raster object.
In ctmcmove: Modeling Animal Movement with Continuous-Time Discrete-Space Markov Chains

Description Usage Arguments Details Value Author(s) References Examples

View source: R/rast.grad.R

This function takes a raster stack or raster object and creates two matrices for each raster layer, one which contains the x coordinates of the gradient of the raster layer and one which contains the y coordinates of the gradient of the raster layer.

1	rast.grad(rasterstack)

rasterstack

A raster layer or raster stack from package "raster".

The gradient is computed using the "terrain" function in raster.

`xy`	A matrix of x and y coordinates of each cell in the raster stack or raster layer. The order is the order of the cells in the raster object.
`grad.x`	a matrix where each column is the x-coordinates of the gradient for one raster layer
`grad.y`	a matrix where each column is the y-coordinates of the gradient for one raster layer
`rast.grad.x`	A raster stack where each raster layer is the x-coordinates of the gradient for one covariate
`rast.grad.y`	A raster stack where each raster layer is the x-coordinates of the gradient for one covariate

Ephraim M. Hanks

Hanks, E. M.; Hooten, M. B. & Alldredge, M. W. Continuous-time Discrete-space Models for Animal Movement The Annals of Applied Statistics, 2015, 9, 145-165

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## For example code, do
##
## > help(ctmcMove)

Loading required package: raster
Loading required package: sp
Loading required package: Matrix
Loading required package: fda
Loading required package: splines

Attaching package: 'fda'

The following object is masked from 'package:graphics':

    matplot

Loading required package: gdistance
Loading required package: igraph

Attaching package: 'igraph'

The following object is masked from 'package:raster':

    union

The following objects are masked from 'package:stats':

    decompose, spectrum

The following object is masked from 'package:base':

    union


Attaching package: 'gdistance'

The following object is masked from 'package:igraph':

    normalize