Discussion Forum

Hi
I would not say complicated, but rather very rich and therefore one need to identify how, and ther are many "how to".

Have you realised that ?
- you can select a "Results - Data set - Solution" node and work on it as reducing by an add selection,
- or you can add functions or operators=evaluation to "Results - Data Set" also on subset.

Then you can call a plot linked to these operators acting on part of your solution

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Good luck
Ivar

Hello Ivar

Thank you very much for your answer.

Best regards

Kostas

Hello,

To complement Ivar's reply, I think the easiest and most elegant way is to define a Domain Point Probe (under Model>Defintions, right-click and select Probes>Domain Point Probe). You can then specify an arbitrary point in the geometry with graphical feedback and also the expression or variable to plot (in a Point Probe Expression subnode). Then, when computing the time-dependent solution, COMSOL displays a graph of the values of this expression or variable at that location in "real time" as the simulation progresses and also creates a plot group and a results table so that both numerical results and a graph are available for further analysis. There are also several other probe types that you can explore.

Best regards,

Magnus Ringh
COMSOL

Hello,

To complement Ivar's reply, I think the easiest and most elegant way is to define a Domain Point Probe (under Model>Defintions, right-click and select Probes>Domain Point Probe). You can then specify an arbitrary point in the geometry with graphical feedback and also the expression or variable to plot (in a Point Probe Expression subnode). Then, when computing the time-dependent solution, COMSOL displays a graph of the values of this expression or variable at that location in "real time" as the simulation progresses and also creates a plot group and a results table so that both numerical results and a graph are available for further analysis. There are also several other probe types that you can explore.

Best regards,

Magnus Ringh
COMSOL

and how can we have several probe plots in different windows (tabs) and not all in one table/tab?

and how can we have several probe plots in different windows (tabs) and not all in one table/tab?

Hello Danial,

By right clicking on the "Results" node, then selecting "1D Plot group". Then go to the new 1D plot Group by left-clicking it, and select the probe you want to see in the "Settings" window. Then right click the 1D plot group and add a point-Graph and you'll have your probe plot in a separate graph.

If you wish to evaluate the tabled-results in separate tables, then open the "Derived values" menu in the Results node by left-clicking the plus in front of it. Right-click the probe you want to see, choose "Evaluate => New table" and you're done !

Best regards,

Ruud Borger,
Comsol

Hi Danial

that is a good suggestion (I have already asked Comsol to consider this for next release, so I hope it will come :)

I would prefer to see the "new plot option" as a tick mnark in the Probe plot definition window.

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Good luck
Ivar

Thank you all very much for the intresting comments

Kostas

hello,

can you please tell me how to select a domain probe point in 3D. It worked in 2D model though, but when i am trying to do it the same way as i did for 2D model, its showing an error at that point.

Thanks in advance.

Hello Magnus,

In response to your Point Probe suggestion, I did try this method and as you mentioned, I could see the real time signal changes as the simulation progressed.
When I export this probe plot in the form of a spreadsheet, I have a huge set of data placed irregularly in time. On the other hand if I go through Derived values --> Boundary probe --> Evaluate in New table, I get exactly the values separated in time as mentioned by me in the Time range of the Time Dependent Study.
The file obtained in the former case is much larger than the latter one. I'm assuming COMSOL takes a longer time in simulation since it produces this large chunk of data very close in time. Is there a way to run the simulation strictly at intervals mentioned in the Step tab of time range using Probe so that only those data values are available for analysis?

I'm not sure if I'm clear enough here but I need to be able to reduce the simulation time, still be able to use Probe analysis, and be able to export data at exact intervals of time.

Your inputs will certainly help.
Thanks.

Sneha