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Creating solution objects and assigning values from MATLAB in COMSOL 4 (similar to femsol)
Posted Sep 9, 2011, 8:24 a.m. EDT Interfacing Version 4.2, Version 4.3a, Version 4.3b 5 Replies
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I am trying to adapt from COMSOL 3.5a to COMSOL 4, and so far, the biggest functionality that I miss while using the MATLAB connection is the following:
I want to be able to create solution objects and assign these solution objects to fem's, so that I can use COMSOL solvers to process the dataset I want, or more importantly, to be able to plot those datasets.
I was able to do this by using the following command in COMSOL 3.5:
fem.sol = femsol(u,'tlist',tlist)
where the solution data set I want to have in fem is present in u. In other words, I was able to manipulate the doffs by manipulating u. Is there a corresponding functionality in COMSOL 4?
Thanks in advance.
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The LiveLink for Matlab contains a function mphgetu that you can use to extract the solution vector.
You can manipulate the solution vector and return it to Comsol using the methods described under setU() in the API Reference Guide.
Lars Gregersen
Comsol Denmark
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Run the code until it gets to the model.sol('sol1').runAll command (to avoid running the solution). Then I run the lines
for i=1:1:length(tlist)
model.sol('sol1').setU(i,U(:,i));
end
model.sol('sol1').setPValues(tlist);
model.sol('sol1').createSolution;
everything but the createSolution method seems to work, but there's problems with createSolution (NullPointerException). Is this a good approach to doing this?
Thanks for any help,
-Matt
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But I can tell you that plotting results in matlab from a .mat file is much faster than the mphplot command. It's better to work with the matlab plot command and your .mat file than trying to "upload" your .mat in a comsol model and working with the slow mphplot command.
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I want to be able to put data back into a solution object so i can use the integration methods from comsol on the mesh. I know I can also juggle with the numerical integration of matlab (trapz() for example), but it is more elegant to make comsol do it, since it has all the dimensions, geometry and mesh already there.
So, anybody found a solution on how to create a solution object with a given data?
( what I do is combine the data from two different datasets with matlab, then i want to integrate certain quantities on this new data set, it has the same number of everything than the original 2).
Thanks!