grdtrend(1gmt) on Linux
The text c4e3a84aebbd, as Debian 8 (Jessie), Debian 7 (Wheezy), Debian 4.0 (Etch), Debian 3.1 (Sarge) shipped it.
Fit and/or remove a polynomial trend in a grd file
Flags it lists
-
-D -
-N -
-T -
-V -
-W