A function to generate an FFT grid and associated
quantities including cell dimensions, size of extended
grid, centroids, cell area, cellInside matrix (a 0/1
matrix: is the centroid of the cell inside the observation
window?)
Usage
genFFTgrid(study.region, M, N, ext, inclusion = "touching")
Arguments
study.region
an owin object
M
number of cells in x direction
N
number of cells in y direction
ext
multiplying constant: the size of the extended
grid: ext*M by ext*N
inclusion
criterion for cells being included into
observation window. Either 'touching' or 'centroid'. The
former includes all cells that touch the observation
window, the latter includes all cells whose centroids are
inside the observation window.