What is penalty value in GA

Hello,

I am a student who is using optimization MATLAB GA toolbox.

Now I'm doing binary optimization include nonlinear constraints.

But, I have ask you something and several problems are occurring in my code.

First, when I plotting a graph, I can see the generation-penalty value(G-P) graph. In here, what is a meaning of penalty value?

It is same function value? (The function value I mean refers to the value of the objective function)

Second, when I look at the G-P graph(below the picture) I got, there is a ridiculous value(it means penalty value) in the previous generation.

Is this a normal?

If that is normal, then why does the front part of generation come out like that?

Answer 1

[Alan Weiss]

The documentation describes the penalty value.

As for the lower-left portion of the plot, these points are infeasible. Once ga finds a feasible point, the penalty value changes. See the description of the penalty value.

Alan Weiss

MATLAB mathematical toolbox documentation