function overloading problem in matlab

Hi guys,

Does matlab support function overloading? Just like, F(x, y) F(x, y, z)

If not, is there any ways to do it?

Thanks,

Zhong

[Kurt Patzik]

Hi,

overloading is possible. However, for simple task I always use nargin instead:

function [ ans ] = fctName( a, b, c )
   if nargin < 2 % checks, if the number of input-parameters is less than 2
       b = 1;
       c = 0;
   end
   ...
end

Best, Jonas

Answer 1

[Daniel Shub]

It is not clear what you are trying to do. I think you might be looking for ways to define a function with a variable number of input arguments. If that is the case

doc varargin

The source of many problems is that MATLAB will let you redefine any function you want. For example

clear = @()disp('Have fun undoing this (:');

will "overload" the builtin CLEAR function. You could also create an mfile named clear.m

function clear(varargin)
  disp('Have fun undoing this (:');
end

which will similarly "overload" CLEAR whenever it is on the path.

The MATLAB OO system allows what I would call true overloading. The OO system choses the exact function that is called based on the name of the function and the class of the first argument.

[Walter Roberson]

Minor addition: the OO system does not take into account the number of arguments. Well, other than the possibility of having no arguments; I don't recall which class is used for that.