Using function of multiple variables in fmincon

I define a function in a separate .m file as:

 function [y]=myfun(r,t,m,n,p)
 syms r,t,p;
 y=limit(diff((p.*exp(1+r.*cos(t)),r,n)),p,1);

 end

I want to use this function in fmincon to minimize over the variables 'r' and 't'.Comments on this problem are welcome. Thanks in advance.

Answer 1

[Matt J]

You want to re-implement myfun as

 function y=myfun(unknowns, n)

    r=unknowns(1);
    t=unknowns(2);

   y = (cos(t).^n) * exp(1+r.*cos(t));

 end

and then

fmincon(@(x) myfun(x,n), [r0,t0], ...other arguments...)

[Shrobona Bagchi]

Hi Matt J, many thanks for your input.Actually I need the function in more general setting like:

function [y]=myfun(r,t,m,n,p)
 syms r,t,p;
 y=limit(diff(((p.^m).*exp(1+r.*cos(t)),r,n)),p,1);
 end

So it will be better if we could keep it in that form otherwise depending on 'm', the expression becomes quite big and cumbersome to write.

Will the method suggested by you work in this case too.

Thanks!

[Matt J]

Following my example or the examples here, you can pass whatever known parameters you want to the function, in addition to the unknowns.

You can also always use matlabFunction to convert a symbolic expression to a non-symbolic Matlab function for use with fmincon, or whatever.

[Shrobona Bagchi]

Thank you for link on additional parameters. It solved the problem.