Simple pixel spacing is used to overlay point locations on a spatial grid, or a series of grids.
mkLookup(x, by.segment = TRUE)
A function, with one argument - a matrix of points - that returns a logical vector indicating the overlay of each point against the masks.
an xyz-list with matrix or array of masks
logical - is the mask to be queried separately for each time step?
Michael D. Sumner
get.mask
and related examples for creating and using
masks.
See over
for more general capabilities for overlays.