q defval/set defval

[Elena A. Yegorova]

Hello GrADS users,

I am trying to use "q defval" and "set defval" to compare two grids
pixel-by-pixel and create a new grid based on the results. This computation
takes a very long time. And my computation is more involved than using
arithmetic formulas of the two grids like grid1-grid2.
Is there a more efficient way for creating a new grid with a unique value
for each grid point (other than set defval)?
Is there a more efficient way to loop through grid points (other than q
defval)?

Thanks for you help.

Elena