thnks for pointing out to cross().........but, if i want to plot fT against wf(width of gate of MOS), i should get 'wf' on the x axis.......but by default, the parameter being swept in the ac simulation controller comes on the x axis....is there a way to get the variable in the 'parameter sweep' to be on the x axis ?......for eg in your case which u showed me in the attached pdf above could we plot, FT against Ibias?............in other words, i want to sweep freq from 1 to 60GHz, i have a single value of parameter sweep variable 'wg' and i compute a single value of fT using the cross() for each entire frequency sweep of 1 to 60GHz......i want a plot of fT against 'wg'...............