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harish_0689@ December 27, 2011 09:47

Matrix solver for Impicit scheme
Hello, I am developing an implicit reimann solver for Euler equations and i am using GMRES algorithm to solve the matrix, but i find that Implicit is taking more CPU time than explicit solver and may be the problem is with the matrix solver. I need some suggestions regarding it as which is the best solver for the implicit schemes and sources from which i can get it?

duri December 27, 2011 11:17

Take advantage of sparse system. Implement GMRES for sparse system.
GMRES can even solve indefinite system. This much advanced solver in not required for Euler equations. Lot of simple, robust solvers are available and they are fast enough. I recommend sparse PCG solver.

harish_0689@ December 28, 2011 09:06

@duri: thanx a lot for the reply...My guide actually suggested me to try out Gauss-seidel point relaxation method..but d problem is i am not able to find the readymade solver..can you suggest me some source from which i can get these readymade PCG or gauss-seidel point relaxation solvers n possibly in C language.

ganesh December 28, 2011 10:17

Dear Harish,

A good open-source package with a large number of built-in linear solvers is LiS. You can find it with documentation at It supports both F90 and C programming languages, but there is not much user-support available. The manual however is self-explanatory and should do the job.



harish_0689@ December 28, 2011 18:56

Thank u very much ganesh. I found it and seems to be helpful..i will try it out.

harish_0689@ January 5, 2012 04:46

@ganesh: I an not able to understand how to integrate the linear solvers you mentioned into my code. Can u please just brief me how to do so..

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