Hi everyone, I was reading about the topic abt inversing a sparse matrix. I have to solve a poisson eqn for my CFD code. Usually, I form a system of linear eqns and solve Ax=b. The "A" is always the same and only the "b" changes every timestep. Does it mean that if I'm able to get the inverse matrix A^(-1), in order to get x at every timestep, I only need to do a simple matrix multiplication ie x=A^(-1)*b ?
Hi Timothy, if the above is true, can you email me your Fortran code template? I'm also programming in fortran 90. Thank you very much Regards. Timothy Stitt wrote: > Yes Yujie, I was able to put together a parallel code to invert a > large sparse matrix with the help of the PETSc developers. If you need > any help or maybe a Fortran code template just let me know. > > Best, > > Tim. > > Waad Subber wrote: >> Hi >> There was a discussion between Tim Stitt and petsc developers about >> matrix inversion, and it was really helpful. That was in last Nov. >> You can check the emails archive >> >> http://www-unix.mcs.anl.gov/web-mail-archive/lists/petsc-users/2007/11/threads.html >> >> >> >> Waad >> >> */Yujie <recrusader at gmail.com>/* wrote: >> >> what is the difference between sequantial and parallel AIJ matrix? >> Assuming there is a matrix A, if >> I partitaion this matrix into A1, A2, Ai... An. >> A is a parallel AIJ matrix at the whole view, Ai >> is a sequential AIJ matrix? I want to operate Ai at each node. >> In addition, whether is it possible to get general inverse using >> MatMatSolve() if the matrix is not square? Thanks a lot. >> >> Regards, >> Yujie >> >> >> On 2/4/08, *Barry Smith* <bsmith at mcs.anl.gov >> <mailto:bsmith at mcs.anl.gov>> wrote: >> >> >> For sequential AIJ matrices you can fill the B matrix >> with the >> identity and then use >> MatMatSolve(). >> >> Note since the inverse of a sparse matrix is dense the B >> matrix is >> a SeqDense matrix. >> >> Barry >> >> On Feb 4, 2008, at 12:37 AM, Yujie wrote: >> >> > Hi, >> > Now, I want to inverse a sparse matrix. I have browsed the >> manual, >> > however, I can't find some information. could you give me >> some advice? >> > >> > thanks a lot. >> > >> > Regards, >> > Yujie >> > >> >> >> >> ------------------------------------------------------------------------ >> Looking for last minute shopping deals? Find them fast with Yahoo! >> Search. >> <http://us.rd.yahoo.com/evt=51734/*http://tools.search.yahoo.com/newsearch/category.php?category=shopping> >> > > > >
