Compare point distances to cell distances
check_cell_distance.RdCheck for discrepancies between pairwise distances between a set of points, versus pairwise distances between the centers of the raster grid cells that the points fall within. There will always be some differences due to the continuous versus discrete nature of the data types, but if discrepancies are large as a percentage of the distances, then they will contribute substantial noise that could invalidate wind connectivity estimates. This function reports how many site pairs are in the same grid cell (an infinite difference that makes wind calculations impossible) as well as information about the distribution of discrepancies as percentages of distance. The more site pairs there are with nontrivial discrepancies, the less reliable a wind connectivity model will be for these sites. Problems identified in this check can be solved using the downscale or vrcd functions.