Questions tagged [petsc]
PETSc is an open source suite of data structures and routines for the scalable (parallel) solution of scientific applications modeled by partial differential equations.
163 questions
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Preconditioning for Large-Scale Incompressible Navier–Stokes (1M+ DOFs) with Stabilized FEM + PETSc
I’m solving the 3D incompressible Navier–Stokes equations in parallel using stabilized finite elements (SUPG + PSPG). The flow is turbulent, with a Reynolds number around
10^6
. The domain has both ...
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Why does my elasto-plastic phase-field fracture model fail at low H/E ratios (linear hardening) and in all nonlinear hardening cases?
I am implementing a 2D elasto-plastic phase-field fracture model under plane strain conditions using a staggered approach. The solver iteratively updates displacement and phase-field damage until ...
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Lack of convergence in a coupled fluid dynamics solver using Newton's method
In my problem, steady fluid flow is considered, and instead of three-dimensional computational fluid dynamics methods, some simplified version is used. I am trying to implement a coupled solution ...
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FEM discretization of Electrical Impedance Tomography on Firedrake or PETSc (or maybe Fenics?)
I am trying to implement a numerical solver for the Complete Electrode Model (CEM) of Electrical Impedance Tomography (EIT). In a domain $\Omega$ with $L\in\mathbb{N}$ electrodes $\Gamma_l\subset\...
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How to approach eigenvalue problem with Schur complement?
In the context of preconditioning saddle point problems (for instance, arising from PDEs) people are interested in solving (generalised) eigenvalue problems associated with the Schur complement $BA^{-...
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Why multigrid is inefficient？
I am trying to solve the Stokes equation containing viscosity nonlinearity using the open source finite element software underworld2 with nested PETSc. The resolution is 2000*200. The solution results ...
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PETSc non-linear solvers (SNES): specifying single Eval & Jacobian function
The PETSc documentation example of a non-linear solver call has the user provide separate functions for the Jacobian and function evaluations:
...
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PETSC: Solving a simpler PDE results in error while solving the original equation works in snes/tutorials/ex13.c
In snes/tutorials/ex13.c,
there is a function SetupPrimalProblem(),
which sets up the $f_0$ and $f_1$ in ...
- 101
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How to efficiently fill in, in parallel, a PETSc matrix from a COO sparse matrix?
Considering the following COO sparse matrix format, with repeated indices:
...
- 294
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How can I optimize the solution of linear systems in my Finite Element Method code for solving nonlinear computational mechanics problems?
Currently, I use Eigen3 for linear algebra operations on sparse matrices and either UMFPACK or CHOLMOD from SuiteSparse to solve sparse linear systems. However, as my model grows larger and the need ...
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Solution of linear system doesn't work, in parallel
I'm solving $Ax = b$ with PETSc, $A$ sparse and asymmetric.
I'm using BCGS or FGMRES or TFQMR as a solver, and ILU as a preconditioner.
When I use 1 core, everything works as expected. But with 8 ...
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Starting point to use Trilinos linear algebra packages?
I have experience with classical linear algebra packages in C++ like Eigen, Blaze, etc.
I have never wrote my own PetSC back-end solver but I used/modified several of them.
In a new project I would ...
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How to reuse the symbolic factorization when using MUMPS in petsc?
I have a problem when using petsc.
I want to solve a series of linear equations.
A1x1=b1, A2x2=b2, A3*x3=b3 ...
The A1,A2,A3 have the same sparstiy pattern.
I want to use MUMPS to solve the system.
In ...
- 323
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PETSc-like library for Julia
I want to build an application for Material Point Method (and probably other meshfree methods too) in Julia and I am looking for library for direct and iterative solvers that can help me with it. One ...
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Output solution vector in Petsc
I am using petsc to solve a linear elasticity problem discretized by finite elements.The initial mesh is read by a mesh file and the distribution in each processor is done using METIS.I am using only ...
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