Use of Function Handle and fmincon in Embedded MATLAB

Hi,

I would like to perform the following 2 lines of code in the MATLAB Function found in the Simulink library (user-defined function):

F = @(x) eval('x(1)^2 + x(2) - 5'); [x,fval] = fmincon(F,x0,[],[],Aeq,beq,lb,ub);

However, I received a coder error saying that: 'This kind of expression is not supported'. Is there any way I can get around this problem?

Any help or suggestion is greatly appreciated! Thanks alot!

Answer 1

[Sean de Wolski]

No need for evil-eval:

F = @(x)x(1)^2 + x(2) - 5;

[rach]

Hi Sean,

The code that I typed above is a simplified version of what I actually have in my code. The actual code is:

F = @(x) eval(costFunction);

[x,fval] = fmincon(F,x0,[],[],Aeq,beq,lb,ub);

where costFunction is a string generated from a rather long and complicated function. Hence, 'eval' is necessary in this case.

The problem I am facing now is that embedded matlab does not seem to be able to handle the function handle. Is there any way to get around this limitation?

Thank you!

[Sean de Wolski]

web([docroot '/toolbox/eml/ug/bsvqvgq.html'])

I'm sorry I do not have more time to look at this now.

Answer 2

[Kaustubha Govind]

As Sean pointed out, here is the documentation about support for function handles with code generation - Code Generation for Function Handles.

Btw, support for function handles was supported for code-generation only added fairly recently. So you might be using an older release where they are not supported in an Embedded MATLAB Function block. In that case, I would recommend defining a MATLAB-file with your code in it:

F = @(x) eval('x(1)^2 + x(2) - 5');
[x,fval] = fmincon(F,x0,[],[],Aeq,beq,lb,ub);

And call that function with the coder.extrinsic (previously eml.extrinsic) directive. Since eval and fmincon are not amongst the functions supported for code-generation, you will have to declare them as extrinsic functions anyway.