genetic algorithm coding help error no enough input arguments?

Objective function

function z=my_fun(a,b,c)

z=a+2*b+56*c+100;

constraint function

function [c]=const(a,b,c)

c=[6<=a<=100;2<=b<=4;2<=c<=4];

Main program

clear all

clc

nvars=3;

lb=[6;2;2];

ub=[100;4;4];

[population_1 fval]=ga(my_fun,nvars,[],[],[],[],[],[],lb,ub,const)

Error when running

Error using my_fun (line 2)

Not enough input arguments.

Error in start (line 6)

[population_1 fval]=ga(my_fun,3,[],[],[],[],[],[],lb,ub,const)

please help me to code sir..

Answer 1

[Alan Weiss]

In addition to what Geoff said, do NOT use your nonlinear constraint function. It appears that you are trying to enforce bounds on your variables. Use bounds to do that, NOT poorly-written nonlinear constraints. I say poorly-written because you do not obey the syntax of nonlinear constraints.

Alan Weiss

MATLAB mathematical toolbox documentation

Answer 2

[Geoff Hayes]

Arunachalam - your function has to many input arguments. Look at the description for the fitness function. It requires a single row vector whose size is determined by the number of variables that you are optimizing over (your function has three inputs). Try changing it to the following

 function z=my_fun(chromosomes)

 a = chromosomes(1);
 b = chromosomes(2);
 c = chromosomes(3);

 z=a+2*b+56*c+100;

[Geoff Hayes]

Arunchalam's answer moved here

Geoff Hayes getting error

Error using my_fun (line 2)

Not enough input arguments.

Error in start (line 6)

[x fval]=ga(my_fun,nvars,[],[],[],[],[],[],lb,ub,const)

[Geoff Hayes]

Arunachalam - yes, you are observing that error message because your my_fun fitness function has too many input arguments. The genetic algorithm calls your fitness function and tries to pass just one array of chromosomes (one element for each variable that you are optimizing over). Your function expects three, and so the error occurs.

Change your fitness function to that which I described in my answer and you should be able to proceed.