A vector (single layer object), matrix (multi-layered object; or if cells=TRUE, or xy=TRUE), Raster* object (if asRaster=TRUE), or SpatialPointsDataFrame (if sp=TRUE)
Arguments
x
Raster object
size
positive integer giving the number of items to choose.
ext
Extent. To limit regular sampling to the area within that box
cells
logical. Also return sampled cell numbers (if asRaster=FALSE)
xy
logical. If TRUE, coordinates of sampled cells are also returned
asRaster
logical. If TRUE, a RasterLayer or RasterBrick is returned, rather than the sampled values
sp
logical. If TRUE, a SpatialPointsDataFrame is returned