Is it possible for OpenModelica to monitor a variable while the simulation is still running? Something like the scope in Matlab Simulink. Currently I'm using OMEdit v1.12.0 and it only plots all the results at the END of the simulation. I'm a newbie with Modelica, I have searched but could not find anything useful.
Try the new interactive simulation
https://openmodelica.org/doc/OpenModelicaUsersGuide/latest/omedit.html#interactive-simulation
Note that you need to download the latest nightly build since its not part of 1.12.
Adeel.
Related
I have a transient model with Modelia.Fluid Valves and Dynamic Pipes that is running slowly. I am trying to find strategies and tools for identifying what is causing the slowness. By following the guidance in the Using the Profiler from OMEdit section of the Modelica Performance Analyzer documentation, I am able to see that the non-linear torn systems of equations are taking most of the CPU time which is helpful. However, I would like to learn more about what is causing the simulation to run slowly.
From reading Automatic tracking of stiff calculations in the models for improving simulation performance, it looks like Dymola has a "State variable logging => Which states that dominate error" option that appears to give insight to what part of the model is causing the integration step size to be reduced. I have read through the OpenModelica Compiler Flags and Simulation Flags documentation and have not found a similar option. Does OpenModelica have a similar option? Are there any tools or options within OpenModelica that will help me understand what parts of my model are causing my model to reduce the step size and run slowly or run slowly for other reasons?
If it matters, I am using the DASSL solver and OpenModelica 1.20.0.
Thanks,
Michael
My problem is that I am running a sweep study with some parameters. I change them in MATLAB and then run a simulation in MATLAB with the sim command. The simulation in SIMULINK contains an external software component from COMSOL with an FEM behind it. In some cases where the configuration is unfavorable (rapid changes in the feedback loop of the controlled system), the FEM tool is not able to converge in finite time, resulting in an error after a few simulation seconds/minutes/hours. The simulation command is inside a try-catch section to avoid that the program is stopped and the next study step starts to process the acquired data.
The problem is that in case the simulation has a convergence problem, the data generated up to this error is not sent to the workspace, but would be valid, and so I cannot find out from the data what was the reason for the convergence problem.
As additional information, I have been using the ToWorkspace block to send the data to my workspace where I do my post processing, and that works fine when the simulation is complete.
If any of you have any ideas on how to solve this problem, maybe you can help me.
Thank you in advance.
I've read that I can generate code from Simulink models/block diagrams. I am curious whether Simulink always converts a model to (c/c++/java) code prior to running a simulation in the Simulink software, and then execute that code? I mean, whenever I'm running a simulation is Matlab converting the block diagram to (c/c++/java) code and running that code behind the scene. In this case, simulation in Simulink directly depends on running some code; this information is important to me in some way.
Generating and running code for a complete model seems plausible, as we can write s-functions using C/Matlab code and use them as custom blocks. So simulating a model involves running code in some degree. Again, since we can write Matlab code as well, simulation may involve interpreting Matlab code in some environment. It makes me curious whether these information are available - how tightly running a simulation in Simulink depends on executing native code in user's machine.
I did some search before posting and found this SO question: How does simulation engine work? Discussion in this question does not answer my question directly.
The answer depens on which mode you chose.
In the normal mode Simulink will run the model as it is primarily using the MATLAB execution engine. No code is generated. Native implemented parts (e.g. S-Functions) are used as individual binaries called by the MATLAB interpreter.
In the accelerator mode Simulink generates model code. This means your full model (except parts where code generation is impossible) is generated and compiled into one binary.
In the rapid accelerator mode not only your model but also the solver is generated and compiled into one binary, now running in a separate process.
For more details refer to the official documentation
I want to make a biometric identification system of the ECG/EKG.
Provided that Matlab does not perform Data Acquisition in Real Time (for monitoring), is there any way to make the monitoring and data acquisition in LabVIEW and then work simultaneously with Matlab for signal processing?
You could just get a matlab compatible daq and run everything in matlab. http://www.mathworks.com/products/daq/
You can indeed do some data acquisition with LabView and work simultaneously with Matlab for signal processing by calling the Matlab script node, which executes some Matlab code during vi execution.
You may have some performance issues, though, because both Labview and Matlab have to run on your machine simultaneously.
Question:
is there any way to make the monitoring and data acquisition on
LabView and then work simultaneously with Matlab for signal processing
Answers:
LabVIEW has "MathScript" node which is basic MatLab built into
an add-on. It is not the MatLab toolboxes. It runs native MatLab
code. It also runs slightly faster LabVIEW updates to the code. If
your code runs there, then LabVIEW will pass data natively
to your code. This box does not have direct MatLab toolbox access, so if
you use any special calls then that can cause a problem.
If you have MatLab on the box, then you can call the external MatLab
function/code using mathscript (link), and the MatLab will run
the function.
Clarification:
Real time just means "bounded time" (link), not "instant". If your idea of bounds are loose enough then many systems can work for them. You do not state it in your question - but what do you consider acceptable response time?
I've worked a lot with LabVIEW and Matlab. Personally, I would not use the Math Scripting node and would opt for using the Matlab Automation Server. You can call Matlab from LabVIEW using the ActiveX palette in LabVIEW (See Functions>>Connectivity>>ActiveX>>Automation Open) A couple reasons why I'd go for ActiveX and NOT the MathScript node:
The Math Script node does not allow you to change code dynamically. You must hardcode your data into the Math Script node and any future changes would require a change to LabVIEW's G code and therefore a recompile of your EXE
The Math Script node does not support all functions when compiled to an executable. Most notably graphing functions. See the help file here to read more on this.
Calling Matlab from ActiveX is going to give you a lot more flexibility in regards to how data is passed and processed.
What is the simplest way to compile m-file without installed matlab?
And can someone say when will users get possibility for compiling programs with training networks (not only using training networks in compiling)?
MATLAB is not a compiled language, it is interpreted at runtime, so you need to have MATLAB installed to run a m-File (script). You can use the MATLAB compiler software to create a standalone application from an m-File or a function.
To run an m-file without having MATLAB, you can use GNU Octave. Octave is an open-source software which has almost the same syntax and functionality as MATLAB. They are not 100% identical though, so you will have to migrate your script. As mentioned in this question, code which runs in MATLAB will almost always run in Octave too, so it should work quite well.
for very basic scripting you can use this online octave(/matlab) compiler I found http://www.tutorialspoint.com/matlab/try_matlab.php There are some limitations of course, but for basic scripts it works well