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[Octave-patch-tracker] [patch #8569] QMR iterative solver
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From: |
Kai Torben Ohlhus |
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Subject: |
[Octave-patch-tracker] [patch #8569] QMR iterative solver |
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Date: |
Mon, 17 Nov 2014 14:32:43 +0000 |
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User-agent: |
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/38.0.2125.122 Safari/537.36 |
Follow-up Comment #1, patch #8569 (project octave):
This code looks good so far, but there are some MATLAB compatibility issues.
Do you have a MATLAB version to compare your results?
n = 100;
on = ones(n,1);
A = spdiags([-2*on 4*on -on],-1:1,n,n);
b = sum(A,2);
tol = 1e-8; maxit = 15;
M1 = spdiags([on/(-2) on],-1:0,n,n);
M2 = spdiags([4*on -on],0:1,n,n);
[x,flag,relres,iter,resvec] = qmr(A,b,tol,maxit,M1,M2);
iter = iter
resvec = resvec
resvec = length(resvec)
MATLAB gets here 9 iterations with a 10x1 resvec of,
your code says 10 iterations with a 1x10 resvec. Maybe the number of
iterations is counted differently?
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