How to solve the error?

for k=1:3:22
    for l=1:3:22
  for i=1:b:M
    for j=1:b:N
        Block(l,k)=L0(i:i+b-1,j:j+b-1);
        A=zeros(200,200);
        A=Block;
        n1=double(Block).*Rot;
        L1=mod(n1,N);
        %K=A1;
%         R1=(L1 + double(A1))
%         m=mod(R1,N);
        %A2=L0(4:6,1:3);
    end
end
  end 
end

I have an image,198x198 matrix. I wanted to get 3x3 matrix,each, from the image and do certain operations. Rot=3x3 matrix R0=200x200 matrix. if i take 3x3 matrix each, from the image, i will get 22 matrices in total. In the program, I want to repeat the process 22 times, so i introduced,k and l terms. But i got an error: Subscripted assignment dimension mismatch.

Error in daru (line 37)
        Block(l,k)=L0(i:i+b-1,j:j+b-1);

Can somebody help me with a loop to repeat it 22 times?

[Guillaume]

See how-to-solve-the-problem which appears to be more or less the same question.

[Darsana P M]

Yes sir,But it is a different code. I have been trying this the whole day. I am trying different codes,but none give me the results. Could somebody help me to solve this.

[Darsana P M]

I am weak in using for loops. Can anyone help me out?

Answer 1

[Jon]

Look closely at your your assignment statement, Block(l,k)=L0(i:i+b-1,j:j+b-1). The left hand side, Block(l,k) is a scalar value. It is just the value of the element in row l, column k, of a matrix called Block. The right hand side is is a matrix with b rows and b columns. You are trying to assign this matrix to a scalar value. The error message is telling you that this does not make sense. You can not assign a matrix to something that should be a scalar value.