If the error message is "Could not locate a solver type for factorization type QR" then you should configure PETSc with --download-suitesparse
Jose > El 26 sept 2022, a las 9:06, fujisan <[email protected]> escribió: > > Thank you Pierre, > > I used PCNONE along with KSPLSQR and it worked. > But as for PCQR, it cannot be found. There is nothing about it in the > documentation as well. > > Fuji > > On Wed, Sep 21, 2022 at 12:20 PM Pierre Jolivet <[email protected]> wrote: > Yes, but you need to use a KSP that handles rectangular Mat, such as KSPLSQR > (-ksp_type lsqr). > PCLU does not handle rectangular Pmat. The only PC that handle rectangular > Pmat are PCQR, PCNONE. > If you supply the normal equations as the Pmat for LSQR, then you can use > “standard” PC. > You can have a look at > https://petsc.org/main/src/ksp/ksp/tutorials/ex27.c.html that covers most of > these cases. > > Thanks, > Pierre > > (sorry for the earlier answer sent wrongfully to petsc-maint, please discard > the previous email) > >> On 21 Sep 2022, at 10:03 AM, fujisan <[email protected]> wrote: >> >> I'm trying to solve Ax=b with a sparse rectangular matrix A (of size 33x17 >> in my test) using >> options '-ksp_type stcg -pc_type lu' on 1 or 2 cpus. >> >> And I always get an error saying "Incompatible vector local lengths" (see >> below). >> >> Here is the relevant lines of my code: >> >> program test >> ... >> ! Variable declarations >> >> PetscCallA(PetscInitialize(PETSC_NULL_CHARACTER,ierr)) >> >> PetscCall(MatCreate(PETSC_COMM_WORLD,A,ierr)) >> PetscCall(MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,m,n,ierr)) >> PetscCall(MatSetType(A,MATMPIAIJ,ierr)) >> PetscCall(MatSetFromOptions(A,ierr)) >> PetscCall(MatSetUp(A,ierr)) >> PetscCall(MatGetOwnershipRange(A,istart,iend,ierr)) >> >> do irow=istart,iend-1 >> ... Reading from file ... >> PetscCall(MatSetValues(A,1,irow,nzv,col,val,ADD_VALUES,ierr)) >> ... >> enddo >> >> PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY,ierr)) >> PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY,ierr)) >> >> ! Creating vectors x and b >> PetscCallA(MatCreateVecs(A,x,b,ierr)) >> >> ! Duplicating x in u. >> PetscCallA(VecDuplicate(x,u,ierr)) >> >> ! u is used to calculate b >> PetscCallA(VecSet(u,1.0,ierr)) >> >> PetscCallA(VecAssemblyBegin(u,ierr)) >> PetscCallA(VecAssemblyEnd(u,ierr)) >> >> ! Calculating Au = b >> PetscCallA(MatMult(A,u,b,ierr)) ! A.u = b >> >> PetscCallA(KSPSetType(ksp,KSPCG,ierr)) >> >> PetscCallA(KSPSetOperators(ksp,A,A,ierr)) >> >> PetscCallA(KSPSetFromOptions(ksp,ierr)) >> >> ! Solving Ax = b, x unknown >> PetscCallA(KSPSolve(ksp,b,x,ierr)) >> >> PetscCallA(VecDestroy(x,ierr)) >> PetscCallA(VecDestroy(u,ierr)) >> PetscCallA(VecDestroy(b,ierr)) >> PetscCallA(MatDestroy(A,ierr)) >> PetscCallA(KSPDestroy(ksp,ierr)) >> >> call PetscFinalize(ierr) >> end program >> >> The code reads a sparse matrix from a binary file. >> I also output the sizes of matrix A and vectors b, x, u. >> They all seem consistent. >> >> What am I doing wrong? >> Is it possible to solve Ax=b with A rectangular? >> >> Thank you in advance for your help. >> Have a nice day. >> >> Fuji >> >> Matrix size : m= 33 n= 17 cpu size: 1 >> Size of matrix A : 33 17 >> Size of vector b : 33 >> Size of vector x : 17 >> Size of vector u : 17 >> [0]PETSC ERROR: --------------------- Error Message >> -------------------------------------------------------------- >> [0]PETSC ERROR: Arguments are incompatible >> [0]PETSC ERROR: Incompatible vector local lengths parameter # 1 local size >> 33 != parameter # 2 local size 17 >> [0]PETSC ERROR: See https://petsc.org/release/faq/ for trouble shooting. >> [0]PETSC ERROR: Petsc Development GIT revision: v3.17.4-1341-g91b2b62a00 >> GIT Date: 2022-09-15 19:26:07 +0000 >> [0]PETSC ERROR: ./bin/solve on a x86_64 named master by fujisan Tue Sep 20 >> 16:56:37 2022 >> [0]PETSC ERROR: Configure options --with-petsc-arch=x86_64 --COPTFLAGS="-g >> -O3" --FOPTFLAGS="-g -O3" --CXXOPTFLAGS="-g -O3" --with-debugging=0 >> --with-cc=mpiicc --with-cxx=mpiicpc --with-fc=mpiifort >> --with-single-library=1 --with-mpiexec=mpiexec --with-precision=double >> --with-fortran-interfaces=1 --with-make=1 --with-mpi=1 >> --with-mpi-compilers=1 --download-fblaslapack=0 --download-hypre=1 >> --download-cmake=0 --with-cmake=1 --download-metis=1 --download-parmetis=1 >> --download-ptscotch=0 --download-suitesparse=1 --download-triangle=1 >> --download-superlu=1 --download-superlu_dist=1 --download-scalapack=1 >> --download-mumps=1 --download-elemental=1 --download-spai=0 >> --download-parms=1 --download-moab=1 --download-chaco=0 --download-fftw=1 >> --with-petsc4py=1 --download-mpi4py=1 --download-saws >> --download-concurrencykit=1 --download-revolve=1 --download-cams=1 >> --download-p4est=0 --with-zlib=1 --download-mfem=1 --download-glvis=0 >> --with-opengl=0 --download-libpng=1 --download-libjpeg=1 --download-slepc=1 >> --download-hpddm=1 --download-bamg=1 --download-mmg=0 --download-parmmg=0 >> --download-htool=1 --download-egads=0 --download-opencascade=0 >> PETSC_ARCH=x86_64 >> [0]PETSC ERROR: #1 VecCopy() at >> /data/softs/petsc/src/vec/vec/interface/vector.c:1607 >> [0]PETSC ERROR: #2 KSPSolve_BiCG() at >> /data/softs/petsc/src/ksp/ksp/impls/bicg/bicg.c:40 >> [0]PETSC ERROR: #3 KSPSolve_Private() at >> /data/softs/petsc/src/ksp/ksp/interface/itfunc.c:877 >> [0]PETSC ERROR: #4 KSPSolve() at >> /data/softs/petsc/src/ksp/ksp/interface/itfunc.c:1048 >> [0]PETSC ERROR: #5 solve.F90:218 >> Abort(75) on node 0 (rank 0 in comm 16): application called >> MPI_Abort(MPI_COMM_SELF, 75) - process 0 >> >
