How can I use anonymous function / cfit in simulink ?

Hello everyone,

I have created several models stored as anonymous functions or cfit objects (I can change for one another, depending on what is the best in that case) in the main workspace.

I would like to use them in Simulink, namely take as input a signal u, and use my function f on it f(u) = y where y will be the output signal in simulink.

So far, I have tried to call them in Matlab Function Block but it doesn't work. For instance, with coder.extrinsic

function y = fcn(u)
y=0;
coder.extrinsic('evalin')
coder.extrinsic('my_fun_in_WS')
fun = evalin('base','my_fun_in_WS');
y = fun(u);
end

It seems that u has not the right type since I get this error Function output 'y' cannot be an mxArray in this context. Consider preinitializing the output variable with a known type.

However, if I put

y = feval(fun,42);

Then the output is correct (constant, equal to fun(42))

Do you have any solution to workout this issue?

Thank you in advance (and sorry for bad english)

Edward

[James Whidborne]

I find it also works ok using an Interpreted MATLAB Fcn block

Answer 1

[Sean de Wolski]

See my answer here:

http://www.mathworks.com/matlabcentral/answers/316742-i-have-a-knn-classification-model-i-want-to-simulate-the-same-in-simulink#answer_247057

EDIT In R2016b, anonymous functions are supported for code generation and thus can be used directly inside of the MATLAB function block:

For cfit, sfit objects you will still need to call those inside of a separate MATLAB function labeled as coder.extrinsic in the MATLAB function block.

[Ezor]

Thanks for that answer. It was not exactly what I was looking for but maybe I could use something similar for anonymous function.

[Sean de Wolski]

See edit.

[Ezor]

Unfortunatly, I have to work on Matlab2014a, but it's good to know !

[Wes Yeagley]

Could you show an example where you use a cfit object in Simulink. I am having trouble calling the cfit object in a separate Matlab function and thus cannot use it in Simulink.