Re: [petsc-users] Estimate memory needs for large grids

Memory use will depend on the preconditioner. This will converge very slowly (i.e., never) without multigrid unless time steps are small. Depending on how rough the coefficients are, you may be able to use geometric multigrid, which has pretty low setup costs and memory requirements. To estimate

[petsc-users] Estimate memory needs for large grids

Hi, I've solving a simple linear equation [ u_t = A*u_xx + A*u_yy + F_t*u ] on a grid size of 55296x55296. I'm reading a vector of that size from an hdf5 file and have the jacobian matrix as a modified 5-point stencil which is preallocated with the following ``` ierr =

Re: [petsc-users] Strange compiling error in DMPlexDistribute after updating PETSc to V3.11.0

On Fri, Apr 5, 2019 at 4:44 PM Danyang Su via petsc-users < petsc-users@mcs.anl.gov> wrote: > Hi All, > > I got a strange error in calling DMPlexDistribute after updating PETSc > to V3.11.0. There sounds no change in the interface of DMPlexDistribute > as documented in > > >

Re: [petsc-users] Solution Diverging

On Fri, Apr 5, 2019 at 5:27 PM Maahi Talukder wrote: > Hi, > Thank you for your reply. > > Well, I have verified the solution on large problems, and I have converged > the solution to machine accuracy using different solvers. So I guess the > setup okay in that respect. > I am suspicious that

Re: [petsc-users] Solution Diverging

So you have a 2D Poisson solver and it is working on large problems but the linear solver is diverging on small problems. I would verify the the solution is good on the large problem. You might have a problem with boundary conditions. What BCs do you think you are using? On Fri, Apr 5, 2019 at

Re: [petsc-users] Strange compiling error in DMPlexDistribute after updating PETSc to V3.11.0

A complete simple code showing this error would be useful. wrt 'Error: Non-variable expression in variable definition context' google gives: https://www.queryxchange.com/q/27_45961166/non-variable-expression-in-variable-definition-context-compilation-error/ But I don't see an expression in the

Re: [petsc-users] Strange compiling error in DMPlexDistribute after updating PETSc to V3.11.0

Ah - the message about distributed_dm - not PETSC_NULL_SF. So I'm off base here.. Satish On Fri, 5 Apr 2019, Balay, Satish via petsc-users wrote: > A fortran interface definition was added in petsc-3.11 so the compile now > checks if its used correctly. > >

Re: [petsc-users] Strange compiling error in DMPlexDistribute after updating PETSc to V3.11.0

A fortran interface definition was added in petsc-3.11 so the compile now checks if its used correctly. http://bitbucket.org/petsc/petsc/commits/fdb49207a8b58c421782c7e45b1394c0a6567048 + PetscSF, intent(out) :: sf So this should be inout? [All auto-generated stubs don't quantify

[petsc-users] Strange compiling error in DMPlexDistribute after updating PETSc to V3.11.0

Hi All, I got a strange error in calling DMPlexDistribute after updating PETSc to V3.11.0. There sounds no change in the interface of DMPlexDistribute as documented in https://www.mcs.anl.gov/petsc/petsc-3.10/docs/manualpages/DMPLEX/DMPlexDistribute.html#DMPlexDistribute

Re: [petsc-users] ASCIIRead error for multiple processors

Ok great, thanks for the explanation! Best, Yuyun From: Matthew Knepley Sent: Friday, April 5, 2019 7:31 AM To: Yuyun Yang Cc: Smith, Barry F. ; petsc-users@mcs.anl.gov Subject: Re: [petsc-users] ASCIIRead error for multiple processors On Fri, Apr 5, 2019 at 10:27 AM Yuyun Yang

Re: [petsc-users] ASCIIRead error for multiple processors

On Fri, Apr 5, 2019 at 10:27 AM Yuyun Yang wrote: > Hmm ok. Then should I use this function or not when I'm reading the input? > It's probably still going to give me the same error and unable to proceed? > > I'd like to know if I should use something else to work around this > problem. > No,

Re: [petsc-users] ASCIIRead error for multiple processors

Hmm ok. Then should I use this function or not when I'm reading the input? It's probably still going to give me the same error and unable to proceed? I'd like to know if I should use something else to work around this problem. Thanks, Yuyun Get Outlook for iOS

Re: [petsc-users] PetscSFReduceBegin can not handle MPI_CHAR?

Junchao's PR has been merged to 'master'. https://bitbucket.org/petsc/petsc/pull-requests/1511/add-signed-char-unsigned-char-and-char Fande Kong via petsc-users writes: > Thanks for the reply. It is not necessary for me to use MPI_SUM. I think > the better choice is MPIU_REPLACE. Doesn’t

Re: [petsc-users] Constructing a MATNEST with blocks defined in different procs

On Fri, Apr 5, 2019 at 7:19 AM Diogo FERREIRA SABINO via petsc-users < petsc-users@mcs.anl.gov> wrote: > Hi, > I'm new in petsc and I'm trying to construct a MATNEST in two procs, by > setting each block of the nested matrix with a MATMPIAIJ matrix defined in > each proc. > I'm trying to use

Re: [petsc-users] error: Petsc has generated inconsistent data, MPI_Allreduce() called in different locations (code lines) on different processors

On Fri, Apr 5, 2019 at 3:20 AM Eda Oktay via petsc-users < petsc-users@mcs.anl.gov> wrote: > Hello, > > I am trying to calculate unweighted Laplacian of a matrix by using 2 > cores. If the size of matrix is in even number then my program works. > However, when I try to use a matrix having odd

[petsc-users] Constructing a MATNEST with blocks defined in different procs

Hi, I'm new in petsc and I'm trying to construct a MATNEST in two procs, by setting each block of the nested matrix with a MATMPIAIJ matrix defined in each proc. I'm trying to use MatCreateNest or MatNestSetSubMats, but I'm not being able to do it. Using MatNestSetSubMats, I'm trying to

Re: [petsc-users] max_it for EPS minres preconditioner

I have made a fix in branch jose/maint/change-maxit-lobpcg It will be included in maint once the nightly tests are clean. Thanks for reporting this. Jose > El 4 abr 2019, a las 23:37, Pieter Ghysels escribió: > > Dear Jose, > > It indeed works correctly when I set maxit after calling EPSSetUp.

[petsc-users] error: Petsc has generated inconsistent data, MPI_Allreduce() called in different locations (code lines) on different processors

Hello, I am trying to calculate unweighted Laplacian of a matrix by using 2 cores. If the size of matrix is in even number then my program works. However, when I try to use a matrix having odd number for size, I guess since size of the matrix cannot be divided into processors correctly, I get the