Can't understand this error in IC610

Hi,

I'm trying to plot the gsd parameter of a MOS transistor during DC
sweep. I have done "save Mppoint" and simulation goes ok. Then from
results browser I'm able to plot gds vs. the sweep parameter in
wavescan. What I wanted to do next was to input this waveform in
calculator, do some processing, namely invert it and plot again. While
I try to plot it from calculator though, I get the following error:

- Warning -
<Calculator>
Evaluation error(ERROR : ("quotient" 0 t nil ("*Error* quotient:
can't handle (1 / nil)"))). Expression: 1/getData("/MN:gds" ?
resultsDir "/home/simulation/HW4_pr3/spectre/schematic" ?result "dc-
dc")

- Warning -
<Calculator>
Evaluation error(Unknown scalar data type: nil). Expression: getData
("/MN:gds" ?result "dc-dc")

As far as I understand it, it says that the denominator is 0 (nil).
However, I just got it from wavescan, so it can't be nil. Even if I
try to put it in the calculator and plot from there, without any
processing it still gives the same error. I tried doing the same
procedure on a regular AC analysis, just plotting node voltages from
results browser and from calculator. It works without a problem. Can
anyone help, please? Thanks

 

one way around this is to plot gds in wavescan, open calculator,
select wave, click on the waveform in wavescan, then change the
calculator expression to 1/waveXY() then plot that. however that won't
work if you want to make than an output in ADE. i'm sure there's a
better way.