How to vectorize matrix assignment process below

I try to vectorized the following code in the following way to speed up the process. But it doesn't work.

I try to use this code to assign some part of the matrix by values as some functions of the index i (a(i), b(i), .etc).

N=100;
A=zeros(2*N,2*N);
for i=2:N-1
A(2*i-1,2*i-1)=a(i);
A(2*i-1,2*i)=b(i);
A(2*i-1,2*i+1)=c(i);
A(2*i,2*i-3)=d(i);
A(2*i,2*i-1)=e(i);
A(2*i,2*i)=f(i);
end

_______________

vectorized code:

N=100;
A=zeros(2*N,2*N);
i=2:N-1;
A(2*i-1,2*i-1)=a(i);
A(2*i-1,2*i)=b(i);
A(2*i-1,2*i+1)=c(i);
A(2*i,2*i-3)=d(i);
A(2*i,2*i-1)=e(i);
A(2*i,2*i)=f(i);

But matlab says the assignment can be carried out because the dimensions doesn't match. So is there any proper way to do this？

[Stephan]

All values from a(i) are overrided by e(i). Same for b(i) and f(i).

[jyp]

Sorry for the typos. I've corrected them.

Answer 1

[KSSV]

Read about sub2ind. Convert your sub indices into global indices and use.

idx = sub2ind(size(A),2*i-1,2*i-1) ;
A(idx) = a(i) ; 

You try to follow something like above.

[jyp]

It works fine. Thanks.