Get maximum number of outputs from anonymous function

Hi everybody. I would like to call a function from within another function. The problem is that i don't know a-priori the number of output variable of the function i'm calling. I can evaluate it with nargout, but once i've done it, how can I call the function with that number of outputs?

function varargout = myfunction(fun, varargin)

   % Do some stuff here

   funName = func2str(fun);
   maxnargout = nargout(funName);
   [??] = fun(varargin{:})

   % Do some stuff here

Using "eval" I could do something like

eval(['[ varargout{1}' sprintf(', varargout{%i}',2:maxnargout ) '] = fun(varargin{:})'])

but it is utterly awful!!!!

Answer 1

[Cam Salzberger]

Hello Luca,

That's a somewhat tricky one, and I agree that going the "eval" route is not the best way. You can get around it using some tricks with cell arrays. Also, I believe that you can use nargout directly on the function handle.

f = @max;
x = rand(3);
results = cell(1, nargout(f));
[results{:}] = f(x);

-Cam

[Luca Amerio]

Wow! It was rather trivial! Didn't think to use the typical [cell{:}] syntax for the output.

Thank you very much

[Stephen23]

@Luca Amerio: you can use comma-separated lists anywhere that you would use a comma-separated list of variables. Very handy!

Answer 2

[Guillaume]

Use the conversion of comma-separated lists to cell array (or structure):

maxnargout = nargout(funName);
out = cell(1, maxnargout);
[out{:}] = fun(varargin{:});

Or if the outputs of fun are meant to go into the varargout of myfunction, then replace out by varargout.