how to pass initial guess to ga(),this is my sample code and i want to initialize complex initial guess in the code please help

Question

Odette 2024-3-11

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2093151-how-to-pass-initial-guess-to-ga-this-is-my-sample-code-and-i-want-to-initialize-complex-initial-gu

评论： Odette 2024-3-12

[z, f] = ga(@objfun,2);
ga stopped because the average change in the fitness value is less than options.FunctionTolerance.
disp(z)
    0.4017    0.4718
function f = objfun(X)
% Create complex value from real and imaginary
z = X(:, 1) + i*X(:, 2); 
f = z.^2 - z + 1;
f = abs(f); 
end

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。

Answer 1

Walter Roberson 2024-3-11

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2093151-how-to-pass-initial-guess-to-ga-this-is-my-sample-code-and-i-want-to-initialize-complex-initial-gu#answer_1423811

In order to pass in an initial guess, you need to create an options structure and set

InitialPopulationMatrix specifies an initial population for the genetic algorithm. The default value is [], in which case ga uses the default CreationFcn to create an initial population. If you enter a nonempty array in the InitialPopulationMatrix, the array must have no more than PopulationSize rows, and exactly nvars columns, where nvars is the number of variables, the second input to ga or gamultiobj. If you have a partial initial population, meaning fewer than PopulationSize rows, then the genetic algorithm calls CreationFcn to generate the remaining individuals.

4 个评论
显示 2更早的评论隐藏 2更早的评论

Walter Roberson 2024-3-12

编辑：Walter Roberson 2024-3-12

在 MATLAB Online 中打开

initial=[1 2];
nvars=2;
opts=optimoptions('ga','InitialPopulationMatrix',initial,'PopulationSize',1);
[z, f] = ga(@objfun,nvars,[],[],[],[],[],[],[],opts);
ga stopped because the average change in the fitness value is less than options.FunctionTolerance.
disp(z)
     1     2
function f = objfun(X)
% Create complex value from real and imaginary
z = X(:, 1) + i*X(:, 2); 
f = z.^2 - z + 1;
f = abs(f); 
end