How to fix in Gauss formula

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Emilia 2020-12-15

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评论： Jon 2020-12-16

采纳的回答： Jon

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Hello,

I have here two formulas of Jacobi and Gauss.

I wrote code in the method Jacobi and it worked for me, but in Gauss there is a problem it came out to me a matrix instead of a vector.

I have a problem with B and c in Gauss, If I did right.

Thanks for the helpers

%Jacobi 
L = tril(A,-1); 
U = triu(A,1);
D = diag(A);
B = -1./D.*(L+U);
c = (1./D).*b;
x_new = B*x+c;
%Gauss 
L = tril(A,-1); 
U = triu(A,1);
D = diag(A);
B = -1./(L+D).*U;
c = (1./(L+D)).*b;
x_new = B*x+c;

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采纳的回答

Jon 2020-12-15

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It looks like in your calculation of c in both the Jacobi and Gauss you should do a Matrix -vector multiply not an element by element so replace yours with

c = (1./D)*b;

and

c = (1./(L+D))*b;

Maybe there are some other issues too.

Also as a comment you compute the same terms multiple times which isn't too efficient, e.g. 1./(L+D) gets computed twice in your Gauss calculation.