Large Matrices for solving linear systems
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Can someone help me, I need to create the pentagonal matrix associated with the Laplace equation.. So -4 along the diagonal and 4 diagonals with 1’s. I want to be able to change the size, initially I was wanting N=33, hence 1024 x 1024.
Also an array with different values, I know I can do b=(ones(N-1)*(N-1),1) with ones or zeros, but is there a way to create a large array with different values.
I have codes for all my methods of solving linear systems, just cant create a matrix A
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Torsten
on 3 Dec 2018
You should think about whether it is necessary to form the matrix explicitly. If N gets larger, this may cause problems with available workspace.
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More Answers (3)
KSSV
on 3 Dec 2018
N = 10 ;
A = diag(ones(N-2,1),-2)+diag(ones(N-1,1),-1)+4*diag(ones(N,1))+........
diag(ones(N-1,1),1)+diag(ones(N-2,1),2) ;
Walter Roberson
on 3 Dec 2018
spdiags() to create the A matrix .
There is no special way to create large dense matrices.
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