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External function in C - error "Wrong architecture"

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Hi,

I am using COMSOL 4.0a on mac os X.

I want to write external functions in C and use these in COMSOL.

Here is an exemple

file add.c

#include "add.h"
int add(int a, int b)
{
return a+b;
}

file add.h
int add(int,int)

I get my library by using

cc -o libadd.dylib add.c -dynamiclib

But when I try to use my library in comsol, I have the error

"wrong architecture"

Does anyone knows what's the trick ?

Thanks for your help,

Sébastien

11 Replies Last Post 15 Nov 2010, 08:37 GMT-5
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Hello Sébastien Janas

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Posted: 10 years ago 4 Nov 2010, 03:31 GMT-4
Nobody have used an external function wrote in C with comsol 4.0a ???
Nobody have used an external function wrote in C with comsol 4.0a ???

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Posted: 10 years ago 4 Nov 2010, 06:41 GMT-4
Hi Sebastien,
if you are trying to solve a numerical problem in C
I suggest you use matlab.
there have been more success with matlab working with comsol than functions written is C.

Hi Sebastien, if you are trying to solve a numerical problem in C I suggest you use matlab. there have been more success with matlab working with comsol than functions written is C.

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Posted: 10 years ago 4 Nov 2010, 06:58 GMT-4
Hi Zvika,

Thanks for your answer.

I have tried this possibility, but I didn't managed to make matlab functions working. Do you have somewhere a good tuto on the use of matlab functions in comsol ?

For exemple, here is what I have tried

a simple function add.m

--------------------------------
function F = add(a,b)
F = a+b;
--------------------------------

I put this file on my desktop, and my desktop is in the path of matlab.

Then I lauch COMSOL and COMSOL SERVER, I connect COMSOL to the server.

I create a MATLAB function with global definitions->function where I put "add" in the function case, and the two arguments a,b in the arguments case.

When I want to use my add function, I have an error "Failed to load library".

Hi Zvika, Thanks for your answer. I have tried this possibility, but I didn't managed to make matlab functions working. Do you have somewhere a good tuto on the use of matlab functions in comsol ? For exemple, here is what I have tried a simple function add.m -------------------------------- function F = add(a,b) F = a+b; -------------------------------- I put this file on my desktop, and my desktop is in the path of matlab. Then I lauch COMSOL and COMSOL SERVER, I connect COMSOL to the server. I create a MATLAB function with global definitions->function where I put "add" in the function case, and the two arguments a,b in the arguments case. When I want to use my add function, I have an error "Failed to load library".

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Posted: 10 years ago 7 Nov 2010, 09:05 GMT-5
when I had problems with my matlab functions in comsol
I contacted the support and it came down to these things:
1. you're function should be able to receive vectors and return vectors.
when you solve your model with a matlab function included, a matlab window need to pop up. if it doesn't you need to check these things:
2. the path where the m file is have to be added to the matlab path.
3. the comsol's setting to know where matlab is should point to where matlab's bin library is
for example C:\Program Files\MATLAB\R2010a\bin

I hope my advices are helful
when I had problems with my matlab functions in comsol I contacted the support and it came down to these things: 1. you're function should be able to receive vectors and return vectors. when you solve your model with a matlab function included, a matlab window need to pop up. if it doesn't you need to check these things: 2. the path where the m file is have to be added to the matlab path. 3. the comsol's setting to know where matlab is should point to where matlab's bin library is for example C:\Program Files\MATLAB\R2010a\bin I hope my advices are helful

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Posted: 10 years ago 8 Nov 2010, 01:10 GMT-5
Great thanks Zvika.

I tried, but it don't works.

Do you connect Comsol to the server when you use a matlab function ?

I have changed the comsol settings in comsol.ini and comsolserver.ini, is there an other file ?

Best regards,

Sébastien
Great thanks Zvika. I tried, but it don't works. Do you connect Comsol to the server when you use a matlab function ? I have changed the comsol settings in comsol.ini and comsolserver.ini, is there an other file ? Best regards, Sébastien

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Posted: 10 years ago 11 Nov 2010, 05:24 GMT-5
Hi, Sebastien

the comsol-matlab connection is made by comsol when you run a matlab function
in comsol. the manual connection is not needed. a small window of matlab should appear when
you run the model.
I suggest you change the comsol settings in all the ini files.
try this as well -
Open a Command Prompt (DOS box) and exeute the following commands

cd C:\Program Files\MATLAB\R2010a\bin
matlab -regserver

then restart

Zvika
Hi, Sebastien the comsol-matlab connection is made by comsol when you run a matlab function in comsol. the manual connection is not needed. a small window of matlab should appear when you run the model. I suggest you change the comsol settings in all the ini files. try this as well - Open a Command Prompt (DOS box) and exeute the following commands cd C:\Program Files\MATLAB\R2010a\bin matlab -regserver then restart Zvika

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Posted: 10 years ago 11 Nov 2010, 09:54 GMT-5

--------------------------------
function F = add(a,b)
F = a+b;
--------------------------------

Sébastien




1. you're function should be able to receive vectors and return vectors.
when you solve your model with a matlab function included, a matlab window need to pop up. if it doesn't you need to check these things:

Zvika



Hi Zvika
please if you guys don't mind i am interest in this discussion also,

going back to Sébastien's matlab function above given a =[2 18 4 0]'; b=[-2 0.051 0 -1]';, hence F is a 4x1 vector

Zvika, were you successful in calling this function in COMSOL40a? if so can you share a simple mph file implementing this matlab function call?

thanks in advance, i just want to make sure we are not pursing a "ghost idea".

--
merci

XIfe
[QUOTE] -------------------------------- function F = add(a,b) F = a+b; -------------------------------- Sébastien [/QUOTE] [QUOTE] 1. you're function should be able to receive vectors and return vectors. when you solve your model with a matlab function included, a matlab window need to pop up. if it doesn't you need to check these things: Zvika [/QUOTE] Hi Zvika please if you guys don't mind i am interest in this discussion also, going back to Sébastien's matlab function above given a =[2 18 4 0]'; b=[-2 0.051 0 -1]';, hence F is a 4x1 vector Zvika, were you successful in calling this function in COMSOL40a? if so can you share a simple mph file implementing this matlab function call? thanks in advance, i just want to make sure we are not pursing a "ghost idea". -- merci XIfe

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Posted: 10 years ago 11 Nov 2010, 20:00 GMT-5
Hi everybody,

In fact, the problem for me was that I am using MATLAB 2008, and it seems that the use of matlab function is only possible with MATLAB 2009. I tried with a version of MATLAB 2009 and it works fine.

Best regards,

Sébastien
Hi everybody, In fact, the problem for me was that I am using MATLAB 2008, and it seems that the use of matlab function is only possible with MATLAB 2009. I tried with a version of MATLAB 2009 and it works fine. Best regards, Sébastien

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Posted: 10 years ago 12 Nov 2010, 10:12 GMT-5
Sébastien,

awesome! please can describe how you did this? i will really be grateful.

did you use Definition - Functions - Analytic or what? to call "add.m" file?


--
merci
Sébastien, awesome! please can describe how you did this? i will really be grateful. did you use Definition - Functions - Analytic or what? to call "add.m" file? -- merci

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Posted: 10 years ago 12 Nov 2010, 12:06 GMT-5
Hi,

In fact it's really simple if you use MATLAB 2009.

In global definition -> function -> matlab I just wrote add in the "function" case and a,b in the "arguments" case.

I have added the path of my function in matlab.

I can use my function add.m in a analytic function of comsol, or in a global variable.

It's a pity that you have to get the last version of matlab to use this functionality. My lab can't buy the new version every year.
Hi, In fact it's really simple if you use MATLAB 2009. In global definition -> function -> matlab I just wrote add in the "function" case and a,b in the "arguments" case. I have added the path of my function in matlab. I can use my function add.m in a analytic function of comsol, or in a global variable. It's a pity that you have to get the last version of matlab to use this functionality. My lab can't buy the new version every year.

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Posted: 10 years ago 15 Nov 2010, 08:37 GMT-5
Hi,

indeed the comsol only works with the most recent matlab 2009,2010.
I forgot to ask if youre using one of those.
I'm happy it works for you.

Zvika
Hi, indeed the comsol only works with the most recent matlab 2009,2010. I forgot to ask if youre using one of those. I'm happy it works for you. Zvika

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