i am getting an error while executing a short code to update a matrix, In an assignment A(I) = B, the number of elements in B and I must be the same. Er

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aqib javed 2016-11-29

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编辑： aqib javed 2016-11-30

A = [0 1 1 1 ;0 0 0 1 ;0 1 0 1 ;0 0 0 0];
N=4; C=2;
rho=0.1;
B= zeros(N,C);
a=[1 0;0 1;1 1;0 1]
for k=1:N-1
    B(k+1) = B(k) + (0.5 * rho* a);
end

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Answer 1

bio lim 2016-11-30

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Not sure if this is what you are trying to do, but I am taking Torsten's approach.

A=[0 1 1 1 ;0 0 0 1 ;0 1 0 1 ;0 0 0 0]; 
N=4; 
C=2; 
rho=0.1; 
B=zeros(N,C,N); 
a=[1 0;0 1;1 1;0 1];
for k=1:N-1 
  B(:,:,k+1) = B(:,:,k) + (0.5 * rho* a); 
end

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bio lim 2016-11-30

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You are making mistakes with indices. Think about the operation you are trying to do here.

B(k+1) = B(k) + (0.5 * a);

a is a matrix, but B(k) gives you a single element of your B matrix. Hence; this operation will give you an error. What you can do is make B a cell matrix.

Aside from that, B is getting updated in the top code.

    B(:,:,1) =
       0     0
       0     0
       0     0
       0     0
B(:,:,2) =
           0.05            0
              0         0.05
           0.05         0.05
              0         0.05
B(:,:,3) =
            0.1            0
              0          0.1
            0.1          0.1
              0          0.1
B(:,:,4) =
           0.15            0
              0         0.15
           0.15         0.15
              0         0.15

aqib javed 2016-11-30

ahan, very nice explanation, i am grateful to you sir, Problem solved now, thanks again

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Answer 2

Torsten 2016-11-29

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You mean

A=[0 1 1 1 ;0 0 0 1 ;0 1 0 1 ;0 0 0 0]; 
N=4; 
C=2; 
rho=0.1; 
B=zeros(N,N,C); 
a=[1 0;0 1;1 1;0 1] 
for k=1:N-1 
  B(k+1,:,:) = B(k,:,:) + (0.5 * rho* a); 
end