Sorry to tell you that this is the wrong place for your question. Your
MUMPS
is the MUltifrontal Massively Parallel sparse direct Solver.
See: http://en.wikipedia.org/wiki/MUMPS_%28software%29
This newsgroup is for the computer language MUMPS, also known as M. This
MUMPS stands for Massachusetts General Hospital Utility Multi-Programming
System.
See: http://en.wikipedia.org/wiki/MUMPS_%28programming_language%29
"LaBird" <b_cheung_2005@[EMAIL PROTECTED]
> wrote in message
news:fd3p61$dn0$1@[EMAIL PROTECTED]
> Dear all,
>
> I am a newbie on using MUMPS 4.7.3 and I have been using it to solve the
> matrix problem AX=B where both A and B are sparse and in double complex
> type. I just modified the zsimpletest.F provided by MUMPS. From the
manual
> I have read that using iterative refinement (ICNTL(10)>0) the solution
can
> be more accurate. However when I tried different positive values of
> ICNTL(10) (I have used 1, 2, 3 and 30) the solution of X provided seems
to
> deviate much further away from the correct solution (I used Matlab as a
> comparison). With ICNTL(10)=0, the result of X is accurate for around
5-7
> decimal places, but with a positive ICNTL(10), it seems the result of X
> becomes wrong; even the order of magnitude for many of the elements does
> not match.
>
> Is it true that I have missed out something that causes the problem?
> Moreover, are there any ways to make my solution more precise? The
values
> of X in my problem solution are often very small, so a precision of 5
d.p.
> may not be good enough. (In particular, I found that the amount of
> non-zeros calculated by MUMPS is much higher than that in Matlab, and by
> calculating the residue value of B-AX, MUMPS gives a value of 10^-7 for
my
> problem while Matlab gives a value of 10^-12.)
>
> Best Regards,
> LaBird (Benny).
> [Email: Please remove all underscores for the correct email address.]
>
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