Re: [petsc-users] PETScFE Point Source

2018-04-13 Thread Matthew Knepley
On Fri, Apr 13, 2018 at 2:07 PM, Stefano Zampini wrote: > What do you mean by point sources? Dirac's delta terms ? If so, these > translates into basis function evaluations , and should not be hard to > support it, but it will require a different API. Matt? > That is

Re: [petsc-users] PETScFE Point Source

2018-04-13 Thread Sanjay Govindjee
Wouldn't it make the most sense to do it in a variationally consistent manner rhs_a = int{ N_a delta(x - x_o) } where x_o is the location of the point source? -sanjay On 4/13/18 7:46 PM, Matthew Knepley wrote: On Fri, Apr 13, 2018 at 1:40 PM, Robert Walker

Re: [petsc-users] PETScFE Point Source

2018-04-13 Thread Stefano Zampini
Il Ven 13 Apr 2018, 21:27 Sanjay Govindjee ha scritto: > Wouldn't it make the most sense to do it in a variationally consistent > manner > > rhs_a = int{ N_a delta(x - x_o) } > > where x_o is the location of the point source? > This is what I meant. However, the current

Re: [petsc-users] PETScFE Point Source

2018-04-13 Thread Matthew Knepley
On Fri, Apr 13, 2018 at 1:51 PM, Robert Walker wrote: > Ok, let me rephrase that...something like way FEniCS (if i remember > correctly) handles this ... between two values with a very small difference > between them on each axis? Is there an example of something like that to >

Re: [petsc-users] PETScFE Point Source

2018-04-13 Thread Matthew Knepley
On Fri, Apr 13, 2018 at 2:37 PM, Stefano Zampini wrote: > Il Ven 13 Apr 2018, 21:27 Sanjay Govindjee ha scritto: > >> Wouldn't it make the most sense to do it in a variationally consistent >> manner >> >> rhs_a = int{ N_a delta(x - x_o) } >> >>

[petsc-users] PETScFE Point Source

2018-04-13 Thread Robert Walker
Hello, Is there an example of application of a point source in one of the tutorial PETScFE style examples? Ideally this would be some point on the interior, and not necessarily on a boundary. Thanks, and apologies in advance if this is a stupid question, Robert Robert L. Walker MS Petroleum

Re: [petsc-users] PETScFE Point Source

2018-04-13 Thread Matthew Knepley
On Fri, Apr 13, 2018 at 2:27 PM, Sanjay Govindjee wrote: > Wouldn't it make the most sense to do it in a variationally consistent > manner > > rhs_a = int{ N_a delta(x - x_o) } > > where x_o is the location of the point source? > That is what Stefano is saying. You can do

Re: [petsc-users] PETScFE Point Source

2018-04-13 Thread Matthew Knepley
On Fri, Apr 13, 2018 at 1:40 PM, Robert Walker wrote: > Hello, > > Is there an example of application of a point source in one of the > tutorial PETScFE style examples? Ideally this would be some point on the > interior, and not necessarily on a boundary. > > Thanks, and

Re: [petsc-users] PETScFE Point Source

2018-04-13 Thread Robert Walker
Ok, let me rephrase that...something like way FEniCS (if i remember correctly) handles this ... between two values with a very small difference between them on each axis? Is there an example of something like that to use as a security blanket from which to expand? Robert Robert L. Walker MS

Re: [petsc-users] PETScFE Point Source

2018-04-13 Thread Stefano Zampini
What do you mean by point sources? Dirac's delta terms ? If so, these translates into basis function evaluations , and should not be hard to support it, but it will require a different API. Matt? Il Ven 13 Apr 2018, 20:51 Robert Walker ha scritto: > Ok, let me rephrase

Re: [petsc-users] Optimal coloring using -snes_fd_color with DMDACreate

2018-04-13 Thread Buesing, Henrik
Great! Thank you! I will have a look at the code and I will also check how much function evaluations are needed in my case. Henrik -- Dipl.-Math. Henrik Büsing Institute for Applied Geophysics and Geothermal Energy E.ON Energy Research Center RWTH Aachen University Mathieustr. 10|

Re: [petsc-users] Change the matrix row order

2018-04-13 Thread
Thanks for your reply! And sorry for my late answer. I want to parallel a particle-method code and solve Ax=b in each timestep. In this code, each partition forms a CSR matrix and assembles the final coefficient matrix by MatCreateMPIAIJWithArrays. But, the domain decomposition makes that the

Re: [petsc-users] FIELDSPLIT preconditioner in parallel

2018-04-13 Thread Rossi, Simone
It looks like the problem was solved in one of the updates. I cannot reproduce that behavior with the latest PETSc. Thanks! I'll let you know if it happens again. Simone From: Smith, Barry F. Sent: Friday, April 13, 2018 10:52:13 AM To:

Re: [petsc-users] Change the matrix row order

2018-04-13 Thread Matthew Knepley
On Fri, Apr 13, 2018 at 5:45 AM, 我 wrote: > > Thanks for your reply! And sorry for my late answer. I want to parallel a > particle-method code and solve Ax=b in each timestep. In this code, each > partition forms a CSR matrix and assembles the final coefficient matrix by >

[petsc-users] teething troubles / MatView() fails silently for transposed seqaij matrix

2018-04-13 Thread Bryan Jurish
morning all, Apologies for what is very probably a boundlessly stupid question. I've just begun exploring PETSc, but find myself stumped by a pretty trivial task. I would like to load a real binary seqaij matrix and save its transposition (also as a binary seqaij matrix) to a different file.

[petsc-users] FIELDSPLIT preconditioner in parallel

2018-04-13 Thread Rossi, Simone
Hello, I'm trying to use PCFIELDSPLIT to solve a two by two block system and it is working pretty nicely (thanks a lot for that!). I'm still having some issues in parallel though: the ksp solver throws an error when one of the fields does not have DOFs on a processor. Is there a way around

Re: [petsc-users] FIELDSPLIT preconditioner in parallel

2018-04-13 Thread Smith, Barry F.
1) Is this with the latest PETSc? some of these issues may have been fixed. 2) Please send use something that reproduces the problem and we will fix it. We aren't aware of this problem. Barry > On Apr 13, 2018, at 9:50 AM, Rossi, Simone wrote: > > Hello, > I'm

Re: [petsc-users] FIELDSPLIT preconditioner in parallel

2018-04-13 Thread Rossi, Simone
I have not tried with the latest version yet. I found this problem in v3.7.7. I'll try that and let you know. If the problem is still there, I'll send you an example. Thanks for the help, Simone From: Smith, Barry F. Sent: Friday, April 13,

Re: [petsc-users] teething troubles / MatView() fails silently for transposed seqaij matrix

2018-04-13 Thread Junchao Zhang
Looks like MatCreateTranspose does not form the transpose, See the notes here . You may want to use MatTranspose . --Junchao