for j=1:10;
    for i=1:10;
        aprox(i,j)=schumaker(vv(:,i,j),nod,agrid);
        aprox2(i,j)=@(x) ppval(aprox(i,j),x);
        a(i,j)=agrid(1);
        b(i,j)= agrid(10);
       [policya(i,j),vvaprox(i,j)]=golden(aprox2(i,j),a(i,j),b(i,j));
end;
end;

where both schumaker and golden are two functions defined in separate m-files. When I used the command:
aprox2(i,j)=@(x) ppval(aprox(i,j),x);
I get an error message instead of a warning as I did with the older version of matlab… I can’t figure out how to fix this.

Thanks in advance!

I recommend following the advice of the error message. Place them in a cell array. E.g.,

fh = { @sin, @cos};
x = 0:.01:1;
ysin = fh{1}(x);

–Loren

MATLAB R2009a corresponds an error ‘Nonscalar arrays of function handles are not allowed; use cell arrays instead’, but it was working before? Is there some common solution how should i change the script to get it working?

Thanks for answers in advance!

Regards,
Ljubomir

You can’t make the function handle local to the file. If you pass a function handle pointing to one file’s subfunction, then that subfunction will be called regardless of where the function handle is passed and whether or not that new context has a function of the same name in its scope. To get that behavior you have to use the strings as you note.

–Loren

Example, if I have

in file qwe1.m:

  function qwe1()
    q.fh = @qwe;
    save('qwe1', 'q');
    qq = load('qwe1');
    qq.q.fh();
  end
  function qwe()
    disp('qwe from qwe1 called')
  end

and in file qwe2.m:

  function qwe2()
    qq = load('qwe1');
    qq.q.fh();
  end
  function qwe()
    disp('qwe from qwe2 called')
  end

Then in Matlab Version 7.5.0.342 (R2007b) I get

  >> qwe1
  qwe from qwe1 called
  >> qwe2
  qwe from qwe1 called

i.e. the function handle de-serialised in qwe2 “remembers” it points to (private) function qwe in qwe1, not qwe2.

I was wondering if it is possible to make the handle local to the source file? Like if a was saving ‘qwe’ as a string and used feval latter to call the (private) function qwe when running qwe2 I would have called the function qwe from qwe2. :-)

Not sure if I am explaining what I know well, here is an example,

in file qwe3.m:

  function qwe3
    q.fs = 'qwe';
    save('qwe3', 'q');
    qq = load('qwe3');
    feval(qq.q.fs);
  end
  function qwe()
    disp('qwe from qwe3 called')
  end

in file qwe4.m:

  function qwe4()
    qq = load('qwe3');
    feval(qq.q.fs);
  end
  function qwe()
    disp('qwe from qwe4 called')
  end

Now when I run in Matlab

  >> qwe3
  qwe from qwe3 called
  >> qwe4
  qwe from qwe4 called

i.e. the 2nd call goes to the qwe function in file qwe4.m (while if this were a file handle would have gone to qwe in qwe3.m).

Thanks for you help,
Ljubomir Josifovski

I find function handles very useful. I use them when I want the code to be flexible. For instance if I want to parse some text with headers. When the parser finds a header ‘HEI’ with some corresponding data, it calls the function parseHEI with the data as argument. This makes the code flexible. Whenever I need a new header I just implement the parsheNEWHEADER function and the everything else is ready to go.

Take a look at str2func. Also in your hei method, just create the function handle you want: fh = @hopp. When you call it with an object of the correct class, the method will get called.

–Loren

methods
   function hei(obj)
     % make function handle to obj.hopp()???
   end

   function hopp(obj,p)
     disp(p)
   end
end