grdgradient(1gmt) on Linux
The text b59f67012c87, as Debian 6.0 (Squeeze), Debian 4.0 (Etch), Debian 3.1 (Sarge) shipped it.
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