You could directly get the gm from the transistor, which doesn't get saved during a swept analysis (e.g. dc sweep or transient). So create an include file called (say) "save.scs" (make sure you have a .scs suffix) containing:
(note that the M1 should be your transistor name). Include this via Setup->Model Libraries.
Then do a dc sweep where you sweep Vbs. And a parametric analysis around that where you sweep Vgs. You can then go to the results browser, and for the dc analysis (not dcOpInfo) plot M1:gm.
In reply to Andrew Beckett:
I created an include file using a text editor in my case
(gedit) and saved is as save.scs which contains save T1:gm the name of my
transistor is T1.
I included this in ADE via Setup-> Model Libraries. First
I did a dc sweep of Vgs from 0 to 1.5 in a linear step Mode of total 100 points.
Then I did and a parametric analysis of
values: Vbs1=-1, Vbs2=-0.75, Vbs3 = -0.5, Vbs4 = -0.25, and
Vbs5 = 0. Then I went to ADE->Tools->Results browser->dc->T1/gm
I got it.
Thank you very much indeed.