Driving a model from Matlab

[David Gadbois]

Greetings,

I'm new to OpenVSP, and am struggling to find documentation on how to drive model parameters in version 3.1.2 using Matlab.  If this has been discussed already, please point me to where.  And thanks in advance for any help.

[James Haley]

David,

I'm not sure of any direct way to drive model parameters via Matlab, 

however I have been using Matlab to generate VSP scripting for the API, then running that via Matlab through the console commands. 

Been using this to generate VSPaero data for sweeps and auto-importing results.

for example,

command = 'vspaero -omp 7 model_DegenGeom';

status = dos(command);

hope this helps,

James Haley

[Rob McDonald]

David,

Sorry I forgot to reply promptly.

If you are doing a typical use-case design study, I recommend you
check out the 'Design File' support in VSP. There are presentations
about it included in the materials from past OpenVSP Workshops.

The Design File capability makes it easy for you to identify certain
variables to vary in a design study -- and then use a simplified file
to set their values. You could easily write that file from Matlab and
then use the built in scripting to automate the analysis you need from
there.

A more advanced approach is possible, but it isn't really ready for
prime time yet. One of my former students made progress on this, but
didn't finish it. He has graduated and is about to start a new full
time job, so he is very busy with life right now.

If you're adventurous, you might try to replicate what he was working on.

He used SWIG to wrap the OpenVSP C++ API with Java. SWIG is a program
for creating wrappers of C/C++ API's to other languages. The OpenVSP
source includes an example of this for Python. (first step, you need
to be able to compile OpenVSP).

Once you've generated a Java wrapper for OpenVSP, it is fairly easy to
call Java from within Matlab.

This will give you direct access to the OpenVSP API (everything that
is available in scripting) from Matlab.

Best of luck,

Rob

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[Brad LaCroix]

James/Rob,

Do you have a working set of files that I can use as a template in MATLAB to get started? I'm trying to go down a similar path with MATLAB where I use MATLAB to run a study in which I vary different parameters and then grab the results to process and plot in MATLAB. However, I'm having trouble getting things setup initially. For example, what does "-omp" mean, "7", and what is inside the file "model_DegenGeom"?

Thanks,

Brad

[James Haley]

Brad,

I don't have a set of Matlab files ready, I have only done a quick execution of this style for vspaero (which is where that 2 line example came from)

The -omp 7 sets the number of cores to run vspaero with, (i7 4 cores - 8 threads)

The model_degengeom is where your degengeom output file should be that you want to do the analysis on.

If you want I can send you my Matlab example after work today, but its very rough around the edges.

[Brad LaCroix]

Hi James,

Thanks for the info. Any example, no matter how rough, would be of great help.

Thanks again,

Brad

[James Haley]

Here is everything you need to run as is. simply place these in the same location as vsp, open in matlab and run. (hopefully).

I tried to comment it out the best I could but this script was just to test if I could do it, not make it user friendly :/

also it I set it to use 1 processing thread only ( I don't know your hardware setup you can change it on line 73 if you want. 

cheers,

James Haley

UTA, AVD lab

[James Haley]

Forgot the data import script. here ya go. 

[Mesut Bilici]

Hi James,

I downladed all codes written in MATLAB and run in the same location as vsp. However, I got an error message like this:

Error using textscan

Mismatch between file and format string.

Trouble reading floating point number from file (row 1u, field 3u) ==> Lunit               \n

in line 52 of importfile.m script.

Can you help about this? I couldn't fix it. 

Thank you.

1 Temmuz 2015 Çarşamba 01:35:35 UTC+3 tarihinde James Haley yazdı: