extend a optimization function in a loop

Question

sajad mhmzd 2021-10-24

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1570768-extend-a-optimization-function-in-a-loop

评论： Walter Roberson 2021-10-25

I want to create some point that distance beteen each two point must not be exceed from a specific value and at the same time these points must be close to each other as more as possible. I use spherical coordinate and wrote this code(for two point). as in each itration a "squre" term adds to the "fun", what's the best way to develope this code for any arbitrary number of point (for example 300 point) without repeating "elseif" loop . I atached my code and "nonlcon" functions

clc
clear
X(1) = 0;
Y(1) = 0;
Z(1) = 0;
for i=2:3
    
    if i == 2
        options = optimoptions('fmincon','MaxFunctionEvaluations',10000,'MaxIterations',5000);
        multiopts = {'MaxIterations','Algorithm','MaxFunctionEvaluations'};
        options2 = resetoptions(options,multiopts);
        fun = @(x)sqrt( (x(1)*cos(x(2))*sin(x(3))-X(i-1))^2 + (x(1)*sin(x(2))*sin(x(3))-Y(i-1))^2 + (x(1)*cos(x(3))-Z(i-1))^2 );
        lb = [2,0,0];
        ub = [2,2*pi,2*pi];
        x0 = [2,4.706221831,3.166020255];
        A = [];
        b = [];
        Aeq = [];
        beq = [];
        nonlcon = @distance;
        [x,fval] = fmincon(fun,x0,A,b,Aeq,beq,lb,ub,nonlcon,options);
        
        X(i) = x(1)*cos(x(2))*sin(x(3));
        Y(i) = x(1)*sin(x(2))*sin(x(3));
        Z(i) = x(1)*cos(x(3));
        
        ROH(i) = x(1);
        THETA(i) = x(2);
        PHI(i) = x(3);
        
    elseif i==3
        options = optimoptions('fmincon','MaxFunctionEvaluations',10000,'MaxIterations',5000);
        multiopts = {'MaxIterations','Algorithm','MaxFunctionEvaluations'};
        options2 = resetoptions(options,multiopts);
        fun = @(x)( sqrt((x(1)*cos(x(2))*sin(x(3))-X(i-1))^2 + (x(1)*sin(x(2))*sin(x(3))-Y(i-1))^2 + (x(1)*cos(x(3))-Z(i-1))^2) + sqrt((x(1)*cos(x(2))*sin(x(3))-X(i-2))^2 + (x(1)*sin(x(2))*sin(x(3))-Y(i-2))^2 + (x(1)*cos(x(3))-Z(i-2))^2) );
        lb = [2,0,0];
        ub = [2,2*pi,2*pi];
        x0 = [2,3.743600534,2.108470198];
        A = [];
        b = [];
        Aeq = [];
        beq = [];
        
        t = i;
        nonlcon = @(x)distance2(x, X, Y, Z, t);
        [x,fval] = fmincon(fun,x0,A,b,Aeq,beq,lb,ub,nonlcon,options);
        
        X(i) = x(1)*cos(x(2))*sin(x(3));
        Y(i) = x(1)*sin(x(2))*sin(x(3));
        Z(i) = x(1)*cos(x(3));
        
        ROH(i) = x(1);
        THETA(i) = x(2);
        PHI(i) = x(3);
    end
end