Genetic Algorithm: how to set a constraint when it does not involve directly the variables.

Both my variables x(1) and x(2) are an input to a stiff ODE problem of 2 equations. My constraints are on the output vectors (y(i)) obtained with the ODE solver ODE23s. Precisely, I want my fitness function to evaluated only when:

(abs(y(1,end)-constant1)<= constant3 && abs(y(2,end)-constant2)<= constant3

Thank you very much.

[John D'Errico]

Can you write the constraint as a function of the variables? Then of course it involves the variables. Directly? What does directly mean here? You can write a function, so what does it matter how direct is the connection? Just write a function that does the call you need.

[Mostapha Dakhchoune]

You were right! it worked.

Thanks again for your answer.