Compute the approximate surface area of cells in an unprojected (longitude/latitude) RasterLayer. It is an approximation because area is computed as the height (latitudial span) of a cell (which is constant among all cells) times the width (longitudinal span) in the (latitudinal) middle of a cell. The width is smaller at the polewards side than at the equator-wards side of a cell. This variation is greatest near the poles and the values are thus not very precise for very high latitudes.
Usage
area(x, ...)
Arguments
x
a Raster* object
...
Additional arguments, see Details
Value
a RasterLayer. Cell values represent the size of the cell in km2
Details
The following additional arguments can be passed, to replace default values for this function
rll{
filename Filename for the output RasterLayer
format Character. Output file type. See writeRasterdatatype Character. Output data type. See dataTypeoverwrite Logical. If TRUE, "filename" will be overwritten if it exists
progress Character. Choose from "text", "window", or "" (the default, no progress bar)
}