grdgradient(1) on Linux
The text 51111d3acf47, as Debian 3.0 (Woody) shipped it. The page shows this text now.
Compute directional derivative or gradient from 2-D grd file representing z(x,y)
Flags it lists
-
-A -
-D -
-G -
-L -
-M -
-N -
-S -
-V