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matlabwrapperbuilt-inoverriding

How to wrap an already existing function with a new function of the same name

Is it possible to create a wrapper around a function that has the exact same name as the original function?

This would be very useful in circumstances where the user wants to do some additional checks on input variables before they are passed on to the built in function How to interrupt MATLAB IDE when it hangs on displaying very large array?

Solution

  • Actually alternatively to slayton's answer you don't need to use openvar. If you define a function with the same name as a matlab function, it will shadow that function (i.e. be called instead).

    To then avoid recursively calling your own function, you can call the original function from within the wrapper by using builtin.

    e.g. 

    outputs = builtin(funcname, inputs..);

    Simple example, named rand.m and in the matlab path:

    function out = main(varargin)
disp('Test wrapping rand... calling rand now...');
out = builtin('rand', varargin{:});

    Note that this only works for functions that are found by builtin. For those that are not, slayton's approach is likely necessary.