calling matlab from fortran program

Hello I have a code in FORTRAN and in part of it I need to carry out some computations with MATLAB. I've written my auxiliary code in MATLAB and Simulink and I want to get a variable(for example "Sens") from FORTRAN and give it to MATLAB, then executing MATLAB code that computes target variable(for example "Amp"),and send "Amp" variable to FORTRAN for running the rest of the main code. In fact I need to call my MATLAB code from FORTRAN. I don't have much skill in FORTRAN but I know MATLAB and Simulink good. I've found in MATLAB central that it is possible to call MATLAB from FORTRAN with MATLAB Engine Functions , Can you please advise me if my work is possible with MATLAB Engine functions and if, how can I do that? I looked into MATLAB documentation about "Calling MATLAB from a Fortran Application", but I didn't understand exactly what to do and this is what I need or not. And is there any easiest way to do my work. Thank you very much

Answer 1

[José-Luis]

Yes, it is possible.

http://www.mathworks.se/help/techdoc/apiref/bqoqnz0.html

I guess, the functions you want to look at are:

Create matlab (numeric array) array:

mxCreateNumericArray

Getting a pointer to the start of the Matlab array so you can populate it with your own data:

mxGetPr

Then you can start a matlab engine:

engOpen

Place your variable in the engine:

engPutVariable

Peform your calculations:

engEvalString

Get your results back (if you don't save to the same variable):

engGetVariable

Close the engine:

engClose

Copy your variable back to FORTRAN if necessary. Deallocate matlab arrays:

mxDestroyArray

Get on with your code... The tricky part (in my experience at least) is to link correctly to the matlab libraries, with the usual fun related to 32bit vs 64bit, different Matlab versions installed, linux vs windows, etc...

Cheers!

[Mohammad Sadegh]

Hi Jose Thank you so much for your replay,

Could you please tell me the steps I should do respectively(in more details)? As I understand I Should use the functions you mentioned in fortran,Is this right ? and what are the requirements for using Matlab Engine? What do you mean by "The tricky part (in my experience at least) is to link correctly to the matlab libraries" ?? Any help would be greatly appreciated.. Thanks

[José-Luis]

It all depends on what you want to do:

Use Fortran code in matlab: mex files

Use matlab code in fortran: matlab engine

A good place to start is the documentation of the C++/Fortran Api.

http://www.mathworks.se/help/techdoc/matlab_external/bp_kqh7.html

You will find quite a few examples in there. For instance an example of using the Matlab engine in FORTRAN (run the following in Matlab's command line).

edit([matlabroot '/extern/examples/eng_mat/fengdemo.F'])

If you want to use the engine; how easy, or how complicated will depend on how familiar you are writing, compiling and linking FORTRAN code. But there is no magic formula. If you are unfamiliar with all this, work your way from the (relatively simple) examples that you can find in the documentation.

[Mohammad Sadegh]

Thank you so much Jose I'm working on it!

[Mohammad Sadegh]

Hi again Jose I'm trying to do what you told for calling matlab from fortran, I started with the matlab example "fengdemo.F" to find out how to do my work. And I copied the example in Compaq visual fortran 6.6 and execute this.but when I execute this program in visual fortran the following errors disappear:

"Error: Syntax error, found ',' when expecting one of: ( : % . = => mwpointer engOpen, engGetVariable, mxCreateDoubleMatrix" Error: Syntax error, found END-OF-STATEMENT when expecting one of: ( : % . = => mwpointer mxGetPr"

what should I do now? :-(( could you please tell me a little more detail about how to do this Thank you a million !

[José-Luis]

I have never used Visual Fortran. The only thing that occurs to me is: do you have your paths set correctly? Is "fintrf.h" in your search path.

[Mohammad Sadegh]

yes it is, I think the matlab engine functions should define for fortran, and "fintrf.h" defines the functions. but the problem is that fortran can't read this file,it seems that .h files is written for C code, not fortran I don't know what to do . How do you use MATLAB Engine ?

[José-Luis]

Check if your compiler is supported. If not, try another one. For example for Matlab 2012a:

hhttp://www.mathworks.se/support/compilers/R2012a/win64.html