| computeAreaRaster {mkde} | R Documentation |
Calculate cell areas from elevation raster.
Description
A lower-level function for calculating a cell area matrix (2D array) from an elevation matrix. The area is based on the surface area of the terrain in the cell. The area matrix is then used in calculating areas of 2.5D MKDES.
Usage
computeAreaRaster(RelevMatrix, RcellSize)
Arguments
RelevMatrix |
A 2D array with elevation values. |
RcellSize |
Size of the cells. It is assumed to be the same in the x and y dimensions. |
Details
This is a wrapper function for C++ function that calculates the surface area of each raster cell given the cell elevations. It is not intended to be used directly; instead, the user should call initializeAreaRaster on an MKDE object.
Value
A 2D matrix of cell surface areas.
Author(s)
Jeff A. Tracey, PhD
USGS Western Ecological Research Center, San Diego Field Station
jatracey@usgs.gov
James Sheppard, PhD
San Diego Zoo Institute for Conservation Research
jsheppard@sandiegozoo.org
References
Jenness J.S. (2004) Calculating landscape surface area from digital
elevation models. Wildlife Society Bulletin 32: 829-839.
Jenness, J.S. (2014) Calculating landscape surface area from
unprojected digital elevation models. In preparation.
Examples
library(terra)
fpath <- system.file("extdata", "condordem.RDS", package="mkde")
condordem <- terra::readRDS(fpath)
cell.sz <- mean(res(condordem))
area.rast <- computeAreaRaster(as.matrix(condordem, wide=TRUE), cell.sz)