Pass Optional Variable in Matlab Genetic Algorithm

Question

I have a problem in coding my Genetic Algorithm using Matlab. I am using the ga function and I have no problem with the concepts of ga and how it works. For implementing my object function, I need to pass an extra variable to this function (In addition to the parameters vector). (What I intend is actually trying to mix fittings of different plot and I am integrating the ga function of Matlab in another code of mine). I have tried using global variables and it works fine. But I was just wondering is there any other solution for this problem? As the global variable starts to become bigger and bigger for later tasks.

Answer 1

You might want to read up on function handles - particularly parameterising function handles. This lets you 'bind in' extra arguments to your objective function. For example, instead of

ga(@myfcn, ...);

You might say

param = 17;
fh = @(x) myfcn(x, param);
ga(fh, ...);

and so myfcn always gets 17 as its second argument.