Parameter sweep issues

[tomhajjar]

I know we discussed this but I'm still seeing issues when doing Parameter sweeps of tubes and FETs. I think the issue may the same for any Parameter sweep using an even number of Points.

In this example below, I want plots of Vgrid=0 -> Vgrid=-max. If I use Start=-5, Stop =0, Step=1, Points=6, the first plot is for Vgs=-0.833 not Vgs=0.

To get the plot Vgs=0, I have to change Points to 5. For this setting it says Step is 1.25 when Step is actually 1.

Tube_6CA7_Push_Pull_prj.zip

[ra3xdh]

The Ngspice and Qucsator has different meaning of "step" and "intervals count" sweep. This issue is explained here #8

[tomhajjar]

So Steps is wrong for ngspice and xyce spice but correct for Qucs. Since Qucsator is being depreciated, is it time to make a change or use the selection of simulator to change the definition?

[cmat21]

It is somewhat confusing to have a difference in DC sweeps using the same settings. Is it planned to correct this difference?

[ra3xdh]

The DC sweep using DC+ParSweep was inherited from old Qucs. Qucsator has no DC sweep simulation and uses this combination instead. It also uses different method to calculate step. The same explantion as here: #8 I will think how to provide a fix and don't break the compatibility between simulators. It is not an obvious task.

[ra3xdh]

Fixed by #615