use optimizer for separated area

i wrote this code

close all
clear all

elementNumb=20;

ubb=90;
lbb=-90;
random_numberst = lbb + (ubb + ubb) * rand(1, elementNumb);        % Random number from -90 to 90

x0 = ( random_numberst) ;     %Initiat delta
ub = zeros(1, elementNumb);  % Initialize a matrix of zeros with 40 elements
ub(1:elementNumb) = ubb;       % Set values from 1 to 21 to 0

lb = zeros(1, elementNumb);  % Initialize a matrix of zeros with 40 elements
lb(1:elementNumb) =lbb;       % Set values from 1 to 21 to 0
[x,fval] = fminimax(@costy,x0,[],[],[],[],lb,ub);

function y = costy(deltaTeta)
freq = 9*10^9;       %Freq
j = sqrt(-1);     %Define Imaginary
l =(3*10^8)/freq;   %Lambda
k = (2*pi)/l;     %Constant
d = 0.5*l;        %Distant of each element
elementNumb = 20;
step = 0.01;
teta1 = ((-1*90):step:(25));
teta2 = ((25):step:(28));
teta3 = ((28):step:(90));
tetat = [teta1,teta2,teta3];
% gg = length(teta1);
jj = length(teta1)+length(teta2);
y = zeros(size(tetat));
    for h = 1:elementNumb
        for t = 1:length(teta1)
        y(t) = y(t)+1 * ( exp(j*(h-1) * (k*d*sind(teta1(t)+deltaTeta(h)))));
        end
             for hh = (length(teta2)+length(teta1)+1):(length(teta3)+length(teta2)+length(teta1))
             y(hh) = y(hh)+ 1 * exp(j*(h-1) * (k*d*sind(teta3(hh-jj)+deltaTeta(h))));
             end
     end          
 end

as you can see i want to minimize some area that it doesnt min

then i run this code here

     elementNumb=20;
    deltaTeta=(x(1:20));
    freq=9*10^9;
    j=sqrt(-1);
    l=(3*10^8)/freq;
    k=(2*pi)/l;
    d=0.5*l;
    xas=90;
    teta=((-1*xas):0.01:(1*xas));
    % deltaTeta=zeros(elementNumb);
    y=0;
    % w=ones(elementNumb);
    for h=1:elementNumb

        y=y+exp(j*(h-1)*(k*d*sind(teta+deltaTeta(h))));

    end
y=y/max(y);

figure;
% 
plot(teta,20*log10(abs(y)),'k')
% 
axis([-100 100 -100 2]);

but the answer is meaningless

the orginal figure is ( deltaTeta=zeros(elementNumb);)

you can see it maximize in 0 but i want change area to teta2

[Alan Weiss]

I would have a better chance of understanding what you are trying to accomplish if you would explain in words what you are attempting. Are you trying to minimize or maximize something? Are you using an optimization solver to do so? You said

"as you can see i want to minimize some area that it doesnt min "

I don't know what that means. I see you have an fminimax call. What is the thing you are trying to minimax? Is it complex-valued? Optimization Toolbox solvers generally work only on real-valued functions (except for least-squares solvers).

Alan Weiss

MATLAB mathematical toolbox documentation

[koorosh dastan]

i explained more here

elementNumb=20;
random_numbersw = rand(1,elementNumb);            % Random number from 0 to 1
ubb=90;
lbb=-90;
random_numberst = lbb + (ubb + ubb) * rand(1, elementNumb);        % Random number from -90 to 90
% random_numberst = 20*(ones(1 , elementNumb));
x0 = [ random_numbersw,random_numberst ] ;
ub = zeros(1, elementNumb*2);  % Initialize a matrix of zeros with 40 elements
ub(1:elementNumb) = 1;       % Set values from 1 to 21 to 0
ub(elementNumb+1:elementNumb*2) = ubb;     % Set values from 22 to 40 to 90
lb = zeros(1, elementNumb*2);  % Initialize a matrix of zeros with 40 elements
lb(1:elementNumb) = 0;       % Set values from 1 to 21 to 0
lb(elementNumb+1:elementNumb*2) = lbb;    % Set values from 22 to 40 to 90

%%
%%Fminimax
options=optimset('disp','iter','LargeScale','off','Diagnostics',...
    'on','TolFun',.000000001,'MaxIter',1000000,'MaxFunEvals',100000);
[x,fval,maxfval,exitflag,output,lambda] = fminimax(@costy,x0,[],[],[],[],lb,ub,[],options);

%%
%%function
function y = costy(deltaTeta)

freq = 9*10^9;       %Freq
j = sqrt(-1);        %Define Imaginary
l =(3*10^8)/freq;    %Lambda
k = (2*pi)/l;        %Constant
d = 0.5*l;           %Distant of each element
elementNumb = 20;
step = 0.1;

teta1 = ((-60)  :step:  (-25));
teta2 = ((-25)  :step:  (11));
teta3 = ((15)    :step:  (20));
teta4 = ((25)   :step:  (50));
teta5 = ((50)   :step:  (60));

tetat = [teta1,teta2,teta3,teta4,teta5];
lenteta1 = length(teta1);
sumLenteta12   = length(teta1) + length(teta2);
sumLenteta123  = length(teta3) + sumLenteta12;
sumLenteta1234 = sumLenteta123 + length(teta4);

g = zeros(elementNumb,length(tetat));

    for h = 1:elementNumb

        %%teta1
        for aa = 1:length(teta1)
         
        g(h,aa) = g(h,aa)+(deltaTeta(h) * ( exp(j*(h-1) * (k*d*sind(teta1(aa)+deltaTeta(h+elementNumb))))));      %w W
        end
        % 
        %%teta2
        for bb=(lenteta1+1):(sumLenteta12)

        g(h,bb) =g(h,bb)+( deltaTeta(h) * exp(j*(h-1) * (k*d*sind(teta2(bb-lenteta1)+deltaTeta(h+elementNumb))))); %with W
        end

        %%teta3

        for cc = (sumLenteta12+1):(length(teta3)+sumLenteta12)
 
        g(h,cc) = g(h,cc)+(-(( deltaTeta(h) * exp(j*(h-1) * (k*d*sind(teta3(cc-sumLenteta12)...
            +deltaTeta(h+elementNumb)))))));  %w W       
        end

        %%teta4

         for dd = (sumLenteta123+1):(sumLenteta123+length(teta4))

          g(h,dd) = g(h,dd)+( deltaTeta(h) * exp(j*(h-1) * (k*d*sind(teta4(dd-(sumLenteta123))...
                 +deltaTeta(h+elementNumb)))));  %w W           

          end
        %teta5

         for ee = (sumLenteta1234+1):(sumLenteta1234+length(teta5))

             g(h,ee) = g(h,ee)+( deltaTeta(h) * exp(j*(h-1) * (k*d*sind(teta5(ee-(sumLenteta1234))...
                 +deltaTeta(h+elementNumb)))));  %w W
         end
    end

y = abs(sum(g,1));

    
 end

i have 5 area (teta) i want my function be in one area max and in another are min

this area is teta3 so i think i should add minus(-) or i should inverse(1/) cost function

but when i add (-) nothing happen or when inverse i got alot of warning