## Re: [Qucs-help] Undefined Variable Problem

 Re: [Qucs-help] Undefined Variable Problem From: Stefan Jahn - 2007-09-12 14:13:48 ```Am Mi, 12.09.2007, 15:56, schrieb E & S Regazzo: Hi! > So it's a single point as opposed to a function of time? Correct. > Is there a way > to combine them on the same graph anyway? Try this equation: Vs_rms_t=PlotVs(linspace(Vs_rms,Vs_rms,length(time)),time) > I also need to include the average DC value of the waveform (peak > voltage / pi) on the graph, as well as working out the DC ripple > voltage. Any suggestions? Same goes then for these... Cheers, Stefan. ```

 [Qucs-help] Undefined Variable Problem From: E & S Regazzo - 2007-09-12 12:38:36 ```Hello, thanks firstly for a great program! I'm trying to create an equation which provides the rms value of a waveform. The equation is: Vs_rms = rms(Vsource.Vt) where Vsource.Vt is the sinusoidal source voltage (transient analysis). I can graph Vsource.Vt, however I end up with the following error when I attempt to simulate the circuit with the equation, and the equation result will not graph. Output: ------- Starting new simulation on Wed 12. Sep 2007 at 22:37:19 creating netlist... done. parsing netlist... checking netlist... checker notice, variable `Vsource.Vt' in equation `Vs_rms' not yet defined netlist content 1 R instances 1 Vac instances 1 Diode instances 1 DC instances 1 TR instances creating netlist... checker notice, variable `Vsource.Vt' in equation `Vs_rms' not yet defined checker notice, variable `Vsource.Vt' in equation `Vs_rms' not yet defined NOTIFY: TR1: average time-step 1.33129e-05, 8017 rejections NOTIFY: TR1: average NR-iterations 2.61729, 0 non-convergences Simulation ended on Wed 12. Sep 2007 at 22:37:20 Ready. Errors: ------- Thanks for any information you can provide. Ewan ```
 Re: [Qucs-help] Undefined Variable Problem From: Stefan Jahn - 2007-09-12 13:13:02 ```Am Mi, 12.09.2007, 14:38, schrieb E & S Regazzo: > Hello, Hi! > thanks firstly for a great program! You're welcome :) > I'm trying to create an equation which provides the rms value of a > waveform. The equation is: > > Vs_rms = rms(Vsource.Vt) > > where Vsource.Vt is the sinusoidal source voltage (transient analysis). > I can graph Vsource.Vt, however I end up with the following error when I > attempt to simulate the circuit with the equation, and the equation > result will not graph. If the name of the source is "Vsource" you'll only have the current through the source "Vsource.It". You actually want to name the node above (or below) the source (one of its terminals), e.g. "source"; then you will have a "source.Vt"... Hope this helps, Stefan. ```
 Re: [Qucs-help] Undefined Variable Problem From: Stefan Jahn - 2007-09-12 13:47:39 ```Am Mi, 12.09.2007, 15:42, schrieb E & S Regazzo: Hi! > Ooops - this is the correct variant... The RMS value is 9. It is a single value. That's why you don't see too much when displayed in a cartesian diagram. Display it in a tabular...then you see it... Hope this works, Stefan. ```
 Re: [Qucs-help] Undefined Variable Problem From: Stefan Jahn - 2007-09-12 13:50:12 ```Am Mi, 12.09.2007, 15:47, schrieb E & S Regazzo: Hi! > Is there any way of setting horizontal cursor bars on the diagrams, or > fine-tuning where the markers are? There are just markers. You can fine-tune its position by selecting the marker, then pressing arrow keys (left/right for first dependency and up/down for second, third, etc. dependency). Cheers, Stefan. ```
 Re: [Qucs-help] Undefined Variable Problem From: Stefan Jahn - 2007-09-12 14:13:48 ```Am Mi, 12.09.2007, 15:56, schrieb E & S Regazzo: Hi! > So it's a single point as opposed to a function of time? Correct. > Is there a way > to combine them on the same graph anyway? Try this equation: Vs_rms_t=PlotVs(linspace(Vs_rms,Vs_rms,length(time)),time) > I also need to include the average DC value of the waveform (peak > voltage / pi) on the graph, as well as working out the DC ripple > voltage. Any suggestions? Same goes then for these... Cheers, Stefan. ```
 Re: [Qucs-help] Undefined Variable Problem From: Stefan Jahn - 2007-09-13 11:57:16 Attachments: Pre-Lab 2.sch ```Am Do, 13.09.2007, 13:34, schrieb E & S Regazzo: > Hi Stefan, Hi Ewan, > the rms plot works - thanks! I'm stumped as to how to plot the DC > average of a waveform. any ideas? Attached the schematic including the DC value... You need two more equations: Vs_dc=real(avg(Vsource.Vt)) Vs_dc_t=PlotVs(linspace(Vs_dc,Vs_dc,length(time)),time) For a full list of equations look at the internal help (press F1 and select description of mathematical functions). Also you can have a look at: ; > Also, is there a way to modify what gets printed out in the Marker > boxes? At the moment, the markers for the RMS values have some > information in them that is distracting: > > Versus.0001: 0.017 > Vs_rms: 9 You can't modify that currently. Probably I'll think about adding the possibility to change data dependencies (also in PlotVs())... Cheers, Stefan.```