MATLAB- passing a function handle parameter into another function as a handle

Working on an assignment involving Genetic Algorithms (loads of headaches, loads of fun). I need to be able to test differing crossover methods and differing mutation methods, to compare their results (part of the paper I have to write for the course). As such, I want to just pass the function names into the Repopulate method, as function handles.

function newpop = Repopulate(population, crossOverMethod, mutat开发者_Go百科ionMethod)
  ...
  child = crossOverMethod(parent1, parent2, @mutationMethod);
  ...

function child = crossOverMethod(parent1, parent2, mutationMethod)
  ...
  if (mutateThisChild == true)
    child = mutationMethod(child);
  end
  ...

The key point here is like 3, parameter 3: how do I pass mutationMethod down another level? If I use the @ symbol, I get told:

"mutationMethod" was previously used as a variable,
 conflicting with its use here as the name of a function or command.

If I don't use the @ symbol, then mutationMethod gets called, with no parameters, and is quite unhappy.

While I am aware that yes, I could just rewrite my code to make it work differently, I'm now curious as to how to make it actually work.

Any help is greatly appreciated.

Actually just dont use the @ symbol, use it when you call the Repopulate function instead. Example:

function x = fun1(a,m)
    x = fun2(a,m);
end

function y = fun2(b,n)
    y = n(b);
end

which we call as:

> fun1([1 2 3], @sum)
6

Refer to the documentation for Passing Function Handle Arguments

Note you can check if the argument is a function handle by: isa(m,'function_handle'). Therefore you can make your function Repopulate more flexible by accepting both a function handle and a function name as a string:

function x = fun(a,m)
    if ischar(m)
        f = str2func(m);
    elseif isa(m,'function_handle')
        f = m;
    else
        error('expecting a function')
    end
    x = fun2(a,f);
end

which now can be called both ways:

fun1([1 2 3], @sum)
fun1([1 2 3], 'sum')