Functions for genetic algorithms

When I run rastriginsfcn.m using optimization toolbox, GA solver, the final value of the fitness function when the algorithm terminated:

Objective function value: 0.05531602101322264 and the final point, which in this example is [0.001 -0.017].

The following are the code for rastriginsfcn.m:

function scores = rastriginsfcn(pop)

% pop = max(-5.12,min(5.12,pop));

scores = 10.0 * size(pop,2) + sum(pop .^2 - 10.0 * cos(2 * pi .* pop),2);

Are the above the complete code for rastriginsfcn.m? How does the code specify the initial population? How does the code specify that this function needs 2 variables (i.e x and y)? How does the code specify that x and y are to be generated randomly?

[Walter Roberson]

I suggest you see http://www.mathworks.co.uk/matlabcentral/answers/52139-global-optimization-for-rastrigin-s-function