Number of variables (nvars) is dependent on the value of one variable when using genetic algorithm (GA)

5 次查看（过去 30 天）

显示更早的评论

Min Zhang 2019-1-30

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/442173-number-of-variables-nvars-is-dependent-on-the-value-of-one-variable-when-using-genetic-algorithm

评论： Min Zhang 2019-1-30

采纳的回答： Walter Roberson

I have two kinds of variables: x and y, and y includes y1, y2, y3, y4, ...

The total number of y's is dependent on the value of x.

For example, if x = 4, then my variables are vars=[x, y1, y2, y3, y4];

if x = 6, then my variables are vars=[x, y1, y2, y3, y4, y5, y6];

In addition, both x and y's are discrete integers, and I have both upper and lower bounds for them.

For example, the options for x is [4, 6, 8, 10];

the options for all the y's (are the same) is [4, 5, 6, 7, 8];

Could GA deal with this problem?

I was thinking to make nvars the potential maximum value.

That is to say, based on the above example, I could make nvars = 1(this is x)+10 (these are 10 y's)=11.

However, I still have issues.

For example, during the optimization process, the value of x could be 6, then there will be only 6 y's, which means the last four variables will be useless (by "useless" I mean there is no need to optimize), then I think I need to set the upper bounds to be same as the lower bounds for these four variables.

But how? Actually, I don't know the value of x when I set the lower and upper bounds, yes?

Thanks in advance!

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Walter Roberson 2019-1-30

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/442173-number-of-variables-nvars-is-dependent-on-the-value-of-one-variable-when-using-genetic-algorithm#answer_358610

Run the system multiple times, one for each of the discrete values of x. Take the best of the solutions.

5 个评论
显示 3更早的评论隐藏 3更早的评论

Walter Roberson 2019-1-30

Yes and Yes.

ga() does not care how you compute the objective function. But it cannot detect that it is working on a case in which one of the variables is unused, and will waste time trying to find values of that variable that lead to a better result. This waste of time can easily lead to it not converging in the number of iterations you give it.

Min Zhang 2019-1-30