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.