there is an error in describing the loop, please help me to resolve this one.

Question

SAHIL SAHOO 2022-8-30

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1790705-there-is-an-error-in-describing-the-loop-please-help-me-to-resolve-this-one

编辑： Rik 2022-8-30

clear
x = linspace (-1,1,256);
y = linspace (-1,1,256);
[X,Y] = meshgrid(x,y);
r = sqrt(X.^2 + Y.^2);
z= 0;
w = 100;
E0 = 1;
O = rand(256,256);
E = E0*exp(-1i*(O)); 
A = (abs(E)).^2 ;
x=linspace(-1,1,256);
[X,Y]=meshgrid(x,x);
r=sqrt(X.^2+Y.^2);
R= 0.06;
t = 0.5;
l= 0:36:360;
M = cell(1,length(l));
for  i = 1:length(l)
    h= t*cosd(l(i));k= t*sind(l(i));
    p=sqrt((X-h).^2+(Y-k).^2);
    M{i}=(p<R);
end
M = M{1}+M{2}+M{3}+M{4}+M{5}+M{6}+M{7}+M{8}+M{9}+M{10};
Io=1.0; 
Y=linspace(1,-1,256); Z=Y ; 
A(1:length(Y),1:length(Z))=0;
for i=1:length(Y)
    for j=1:length(Z)
        q=(Y(i).^2+Z(j).^2).^0.5;
        w = 0.3;
        A(i,j)=Io.*exp(-((q.^2)./w^2));
    end
end
G0 = 15;
I = 1;
E = E0*exp(-1i*(O)); 
for i = 1:100
    G(i) = G0/(1+ (abs(E(i)))^2/I);
    E(i+1) = M *(ifft(A*(fft(G* E(i)))));
end
Unable to perform assignment because the left and right sides have a different number of elements.
imagesc(E)

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Rik 2022-8-30

So the question is: what do you want to do?

Answering that question is very hard because you chose non-descriptive variable names and didn't write any comments. How do you expect anyone to understand what is going on in your code? Remember that you in three months time are a different person from current you. How is future you suposed to understand what you did and extend functionality or fix a bug?

SAHIL SAHOO 2022-8-30

在 MATLAB Online 中打开

@Karim please check this one.

clear
x = linspace (-1,1,256);
y = linspace (-1,1,256);
[X,Y] = meshgrid(x,y);
r = sqrt(X.^2 + Y.^2);
z= 0;
w = 100;
E0 = 1;
O = rand(256,256);
E = E0*exp(-1i*(O)); 
A = (abs(E)).^2 ;
x=linspace(-1,1,256);
[X,Y]=meshgrid(x,x);
r=sqrt(X.^2+Y.^2);
R= 0.06;
t = 0.5;
l= 0:36:360;
M = cell(1,length(l));
for  i = 1:length(l)
    h= t*cosd(l(i));k= t*sind(l(i));
    p=sqrt((X-h).^2+(Y-k).^2);
    M{i}=(p<R);
end
M = M{1}+M{2}+M{3}+M{4}+M{5}+M{6}+M{7}+M{8}+M{9}+M{10};
Io=1.0; 
Y=linspace(1,-1,256); Z=Y ; 
A(1:length(Y),1:length(Z))=0;
for i=1:length(Y)
    for j=1:length(Z)
        q=(Y(i).^2+Z(j).^2).^0.5;
        w = 0.3;
        A(i,j)=Io.*exp(-((q.^2)./w^2));
    end
end
% i want to apply loop here by using numerate or any for loop but i didn't how i can do
% that.
G0 = 15;
I = 1;
E1 = E0*exp(-1i*(O));
G1 = G0./(1+ (abs(E1))^2/I);
E2 = M *(ifft(A*(fft(G1* E1))));
G2 = G0./(1+ (abs(E2))^2/I);
E3 = M *(ifft(A*(fft(G2* E2))));
G3 = G0./(1+ (abs(E3))^2/I);
E4 = M *(ifft(A*(fft(G3* E3))));
G4 = G0./(1+ (abs(E4))^2/I);
E5 = M *(ifft(A*(fft(G4* E4))));
G5 = G0./(1+ (abs(E5))^2/I);
E6 = M *(ifft(A*(fft(G5* E5))));
G6 = G0./(1+ (abs(E6))^2/I);
E7 = M *(ifft(A*(fft(G6* E6))));
G7 = G0./(1+ (abs(E7))^2/I);
E8 = M *(ifft(A*(fft(G7* E7))));
G8 = G0./(1+ (abs(E8))^2/I);
E9 = M *(ifft(A*(fft(G8* E8))));
G9 = G0./(1+ (abs(E9))^2/I);
E10 = M *(ifft(A*(fft(G9* E9))));
G10 = G0./(1+ (abs(E10))^2/I);
E = M *(ifft(A*(fft(G10* E10))));
imagesc((abs(E)).^2);colorbar

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Answer 1

Rik 2022-8-30

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1790705-there-is-an-error-in-describing-the-loop-please-help-me-to-resolve-this-one#answer_1037980

编辑：Rik 2022-8-30

在 MATLAB Online 中打开

init.m

If you're not planning to do anything with the intermediate values, why would you store them?

init % Runs the first part of your code.

G0 = 15;

I = 1;

E = E0*exp(-1i*(O));

for iteration=1:10

G = G0./(1+ (abs(E))^2/I);

E = M *(ifft(A*(fft(G* E))));

end

imagesc((abs(E)).^2);colorbar

If you want to store the intermediate numbers, that is also possible: use cell vectors. That will you give more intutive control. Just remember that Matlab uses 1-indexing, not 0-indexing.

G0 = 15;

I = 1;

E = { E0*exp(-1i*(O)) };

G = { G0./(1+ (abs(E{1}))^2/I) };

for ind=2:10

E{ind} = M *(ifft(A*(fft(G{ind-1}* E{ind-1}))));

G{ind} = G0./(1+ (abs(E{ind}))^2/I);

end

E_final = M *(ifft(A*(fft(G{10}* E{10}))));

imagesc((abs(E_final)).^2);colorbar