<div dir="ltr">Dear all,<div><br></div><div>I'm trying to use the KSP solver with nested matrix and vector. If I do not call KSPSetup it goes just fine. When I call the KSPSetUp I am getting the following error</div><div><br></div><div><div>[0]PETSC ERROR: Invalid argument</div><div>[0]PETSC ERROR: Nest vector arguments 1 and 2 have different numbers of blocks.</div><div>[0]PETSC ERROR: See <a href="http://www.mcs.anl.gov/petsc/documentation/faq.html" target="_blank">http://www.mcs.anl.gov/petsc/documentation/faq.html</a> for trouble shooting.</div><div>[0]PETSC ERROR: Petsc Development GIT revision: unknown  GIT Date: unknown</div><div>[0]PETSC ERROR: ./test on a linux-gnu-cxx-real-opt named eden by adam Sat Feb  7 21:48:02 2015</div><div>[0]PETSC ERROR: Configure options PETSC_DIR=/home/adam/libs/petsc PETSC_ARCH=linux-gnu-cxx-real-opt --with-x=0 --with-mpi=1 --with-debu</div><div>gging=0 --with-clanguage=cxx --with-c-support=0 --with-scalar-type=real --download-sowing=linux/packages/sowing-1.1.16g.tar.gz --download-c2html=linux/packages/c2html.tar.gz --with-blas-lapack-lib="-L/home/adam/libs/lapack/lib -lopenblas" --download-scalapack=linux/packages/scalapack-2.0.2.tgz --download-metis=linux/packages/metis-5.0.2-p3.tar.gz --download-ptscotch=linux/packages/scotch_6.0.0_esmumps.tar.gz --download-parmetis=linux/packages/parmetis-4.0.2-p5.tar.gz --download-mumps=linux/packages/MUMPS_4.10.0-p3.tar.gz --download-pastix=linux/packages/pastix_5.2.2.20.tar.bz2 --download-superlu_dist=linux/packages/superlu_dist_3.3.tar.gz --download-hypre=linux/packages/hypre-2.10.0b.tar.gz                                                                                                               [0]PETSC ERROR: #1 VecCopy_Nest() line 76 in /home/adam/libs/petsc/src/vec/vec/impls/nest/vecnest.c</div><div>[0]PETSC ERROR: #2 VecCopy() line 1675 in /home/adam/libs/petsc/src/vec/vec/interface/vector.c</div><div>[0]PETSC ERROR: #3 KSPInitialResidual() line 59 in /home/adam/libs/petsc/src/ksp/ksp/interface/itres.c</div><div>[0]PETSC ERROR: #4 KSPSolve_GMRES() line 234 in /home/adam/libs/petsc/src/ksp/ksp/impls/gmres/gmres.c</div><div>[0]PETSC ERROR: #5 KSPSolve() line 547 in /home/adam/libs/petsc/src/ksp/ksp/interface/itfunc.c</div><div>[0]PETSC ERROR: #6 main() line 36 in /home/adam/develop/test/src/test.cc</div><div>[0]PETSC ERROR: PETSc Option Table entries:</div><div>[0]PETSC ERROR: -ksp_monitor</div><div>[0]PETSC ERROR: -ksp_view</div><div>[0]PETSC ERROR: ----------------End of Error Message -------send entire error message to petsc-maint@mcs.anl.gov----------</div></div><div><br></div><div>I have attached a simple example to show this problem.</div><div><br></div><div>Best regards,</div><div>Ce Qin</div><div><br></div></div>