In order to enable the procedure to operate on as arbitary grid as possible, the All_Dist_From_i keyword calculates the distances between all possible combinations of points in the source and interpolated grids. For typical grid sizes (for, say, a regional climate model), this generally results in a very large array. Ideally, I should have written the keyword so only those points within a specified distance (say a few Search_Radius) are stored, but this would require rewriting some significant parts of the procedure. Maybe someday I'll get to it.