[CIG-SHORT] [EXTERNAL] Why does it not converge?

[Brad Aagaard]

Tu Xiang,

Please provide a detailed description of the problem you are trying to 
solve. Include information such as the geometry of the domain, what bulk 
constitutive models you are using, what boundary conditions are you 
applying, etc. A diagram is usually most helpful. Also please send the 
entire log of the output. If you want to send input files or the files 
are more than 1 MB, please put them in a gzipped tarball or zip file.

Regards,
Brad


On 06/11/2018 03:46 AM, tu xiang wrote:
> Hello,
> I constructed a 2-D model to model static coseismic deformation. But 
> Pylith report errors:
> 
> Linear solve did not converge due to DIVERGED_ITS iterations 400
> [0]PETSC ERROR: --------------------- Error Message 
> --------------------------------------------------------------
> [0]PETSC ERROR:
> [0]PETSC ERROR: KSPSolve has not converged
> [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html 
> for trouble shooting.
> [0]PETSC ERROR: Petsc Development GIT revision: v3.7.6-4826-gd686aaf 
>   GIT Date: 2017-08-03 14:01:44 -0500
> [0]PETSC ERROR: 
> /home/work/pylith/pylith-2.2.1-linux-x86_64/bin/mpinemesis on a 
> arch-pylith named insar.geodyn by Mon Jun 11 18:39:17 2018
> [0]PETSC ERROR: Configure options --prefix=/home/brad/pylith-binary/dist 
> --with-c2html=0 --with-x=0 --with-clanguage=C --with-mpicompilers=1 
> --with-debugging=0 --with-shared-libraries=1 --with-64-bit-points=1 
> --with-large-file-io=1 --download-chaco=1 --download-ml=1 
> --download-f2cblaslapack=1 --with-hwloc=0 --with-ssl=0 --with-x=0 
> --with-c2html=0 --with-lgrind=0 --with-hdf5=1 
> --with-hdf5-dir=/home/brad/pylith-binary/dist --with-zlib=1 --LIBS=-lz 
> --with-fc=0 CPPFLAGS="-I/home/brad/pylith-binary/dist/include " 
> LDFLAGS="-L/home/brad/pylith-binary/dist/lib 
> -L/home/brad/pylith-binary/dist/lib64 " CFLAGS="-g -O2" CXXFLAGS="-g -O2 
> -DMPICH_IGNORE_CXX_SEEK" FCFLAGS= 
> PETSC_DIR=/home/brad/pylith-binary/build/petsc-pylith PETSC_ARCH=arch-pylith
> [0]PETSC ERROR: #1 KSPSolve() line 855 in 
> /home/brad/pylith-binary/build/petsc-pylith/src/ksp/ksp/interface/itfunc.c
> [0]PETSC ERROR: #2 void 
> pylith::problems::SolverLinear::solve(pylith::topology::Field*, 
> pylith::topology::Jacobian*, const pylith::topology::Field&)() line 132 
> in ../../../pylith-2.2.1/libsrc/pylith/problems/SolverLinear.cc
> Fatal error. Calling MPI_Abort() to abort PyLith application.
> Traceback (most recent call last):
>    File 
> "/home/work/pylith/pylith-2.2.1-linux-x86_64/lib/python2.7/site-packages/pylith/apps/PetscApplication.py", 
> line 74, in onComputeNodes
>      self.main(*args, **kwds)
>    File 
> "/home/work/pylith/pylith-2.2.1-linux-x86_64/lib/python2.7/site-packages/pylith/apps/PyLithApp.py", 
> line 138, in main
>      self.problem.run(self)
>    File 
> "/home/work/pylith/pylith-2.2.1-linux-x86_64/lib/python2.7/site-packages/pylith/problems/TimeDependent.py", 
> line 155, in run
>      self.formulation.step(t, dt)
>    File 
> "/home/work/pylith/pylith-2.2.1-linux-x86_64/lib/python2.7/site-packages/pylith/problems/Implicit.py", 
> line 212, in step
>      self.solver.solve(dispIncr, self.jacobian, residual)
>    File 
> "/home/work/pylith/pylith-2.2.1-linux-x86_64/lib/python2.7/site-packages/pylith/problems/problems.py", 
> line 166, in solve
>      def solve(self, *args): return _problems.SolverLinear_solve(self, 
> *args)
> RuntimeError: Error detected while in PETSc function.
> application called MPI_Abort(MPI_COMM_WORLD, -1) - process 0
> /home/work/pylith/pylith-2.2.1-linux-x86_64/bin/nemesis: mpirun: exit 255
> /home/work/pylith/pylith-2.2.1-linux-x86_64/bin/pylith: 
> /home/work/pylith/pylith-2.2.1-linux-x86_64/bin/nemesis: exit 1
> 
> 
> I do not know why. Why does it not converge?
> 
> Hope someone could please give me some advice.
> 
> Tu Xiang