Mannually specify a diagonal matrix as a preconditioner?

2008-03-31 Thread Matthew Knepley
On Mon, Mar 31, 2008 at 5:44 PM, Shi Jin wrote: > > > > Then my answer is the same as my second answer. To first order, I think > the time > > is completely negligible, so just use an AIJ matrix. If, after measuring > the > > performance, you are unhappy, then put the diagonal matrix in a vector a

Mannually specify a diagonal matrix as a preconditioner?

2008-03-31 Thread Matthew Knepley
On Mon, Mar 31, 2008 at 5:05 PM, Shi Jin wrote: > > > You do not need another matrix to do lumping. Just give the mass matrix in > both arguments, and then use > > -pc_type jacobi -pc_jacobi_rowsum > > Matt > > Thank you Matt. > However, I want to do more than a row sum, which is perfectly fin

Non repeatability issue

2008-03-31 Thread Aldo Bonfiglioli
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Create a pure diagonal matrix

2008-03-31 Thread Matthew Knepley
Using a combination of Jacobi and KSP scaling, you almost never need a diagonal matrix in solves. However, if you really do, I would just use MatDiagonScale(): http://www-unix.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-current/docs/manualpages/Mat/MatDiagonalScale.html#MatDiagonalScale and if you

Mannually specify a diagonal matrix as a preconditioner?

2008-03-31 Thread Matthew Knepley
You do not need another matrix to do lumping. Just give the mass matrix in both arguments, and then use -pc_type jacobi -pc_jacobi_rowsum Matt On Mon, Mar 31, 2008 at 4:04 PM, Shi Jin wrote: > > Hi there, > > I am trying to solve a mass matrix linear system by KSPSolve. Right now, I > am p

Mannually specify a diagonal matrix as a preconditioner?

2008-03-31 Thread Shi Jin
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Mannually specify a diagonal matrix as a preconditioner?

2008-03-31 Thread Shi Jin
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Create a pure diagonal matrix

2008-03-31 Thread Shi Jin
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Mannually specify a diagonal matrix as a preconditioner?

2008-03-31 Thread Shi Jin
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PETSc installation problem

2008-03-31 Thread Tim Kroeger
Dear PETSc team, I found the problem myself now -- it was a wrong setting in LD_LIBRARY_PATH. Sorry for the posting. Tim On Mon, 31 Mar 2008, Tim Kroeger wrote: > Dear PETSc team, > > When trying to install PETSc-2.3.3-p11, I get the following output from > ./config/configure.py: > > Traceba

PETSc installation problem

2008-03-31 Thread Tim Kroeger
Dear PETSc team, When trying to install PETSc-2.3.3-p11, I get the following output from ./config/configure.py: Traceback (most recent call last): File "./config/configure.py", line 298, in petsc_configure([]) File "./config/configure.py", line 210, in petsc_configure import cPi