Re: [petsc-users] Coupled system of equations on unstructured mesh

On Sun, Sep 10, 2023 at 4:16 PM Karthikeyan Chockalingam - STFC UKRI < karthikeyan.chockalin...@stfc.ac.uk> wrote: > Thank you. I almost got it and have a couple of questions. > > > > Let me summarize, I have an element Jacobian matrix of size 8 x 8 for > QAUD4 (for variables u and v) ordered such

Re: [petsc-users] Coupled system of equations on unstructured mesh

Thank you. I almost got it and have a couple of questions. Let me summarize, I have an element Jacobian matrix of size 8 x 8 for QAUD4 (for variables u and v) ordered such that the degrees of freedom at a node are grouped together i.e. [u1 v1 u2 v2 u3 v3 u4 v4]. Q1) But this ordering of element

[petsc-users] Generally constrained solvers with FenicsX

Hi all, I've been struggling for some time now trying to get a generally constrained solver (ideally ALMM, but PDIPM might work too) to work in python, specifically with FEniCS X. My model is an incremental variational approach to plasticity and normally requires two lagrange multipliers alongside

Re: [petsc-users] Coupled system of equations on unstructured mesh

On Sun, Sep 10, 2023 at 3:15 PM Karthikeyan Chockalingam - STFC UKRI < karthikeyan.chockalin...@stfc.ac.uk> wrote: > I don’t see an option to give block size. > > https://petsc.org/release/manualpages/Mat/MatCreateAIJ/ > https://petsc.org/release/manualpages/Mat/MatSetBlockSize/ Thanks,

Re: [petsc-users] Coupled system of equations on unstructured mesh

I don’t see an option to give block size. https://petsc.org/release/manualpages/Mat/MatCreateAIJ/ Many thanks, Karthik. From: Matthew Knepley Date: Sunday, 10 September 2023 at 20:09 To: Chockalingam, Karthikeyan (STFC,DL,HC) Cc: petsc-users@mcs.anl.gov Subject: Re: [petsc-users] Coupled syst

Re: [petsc-users] Coupled system of equations on unstructured mesh

On Sun, Sep 10, 2023 at 3:01 PM Karthikeyan Chockalingam - STFC UKRI < karthikeyan.chockalin...@stfc.ac.uk> wrote: > I will solve the coupled problem in a non-linear fashion using SNES, so I > will have one residual for each variable R(u1) and R(u2) and the resulting > Jacobian matrix > > > > J =

Re: [petsc-users] Coupled system of equations on unstructured mesh

I will solve the coupled problem in a non-linear fashion using SNES, so I will have one residual for each variable R(u1) and R(u2) and the resulting Jacobian matrix J = [J11 J12 J21 J22] for each element. For first-order Lagrange elements (in 2D) will have four nodes, then J would be

Re: [petsc-users] Error while running with -pc_type gamg on NVIDIA GPU

> On Sep 10, 2023, at 5:54 AM, Maruthi NH wrote: > > Hi all, > > I am trying to accelerate the linear solver with PETSc GPU backend. For > testing I have a simple 1D heat diffusion solver, here are some observations. > 1. If I use -pc_type gamg it throws the following error > ** On entry t

Re: [petsc-users] Coupled system of equations on unstructured mesh

On Sun, Sep 10, 2023 at 1:48 PM Karthikeyan Chockalingam - STFC UKRI via petsc-users wrote: > Hello, > > > > I have so far solved scalar field problems using finite elements on a > given (*unstructured*) mesh. I made use of MATMPIAIJ to create matrixes, > MatCreateVecs(A, &b, &x) to create vector

[petsc-users] Coupled system of equations on unstructured mesh

Hello, I have so far solved scalar field problems using finite elements on a given (unstructured) mesh. I made use of MATMPIAIJ to create matrixes, MatCreateVecs(A, &b, &x) to create vectors, and MatZeroRowsColumnsIS to set boundary conditions. Now, I would like to solve a coupled system of eq

[petsc-users] Error while running with -pc_type gamg on NVIDIA GPU

Hi all, I am trying to accelerate the linear solver with PETSc GPU backend. For testing I have a simple 1D heat diffusion solver, here are some observations. 1. If I use -pc_type gamg it throws the following error ** On entry to cusparseCreateCsr() parameter number 5 (csrRowOffsets) had an illega