<div dir="ltr"><div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:large">I did configure Petsc with the option --download-suitesparse.</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:large"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:large">The error is more like this:</div><div class="gmail_default"><font face="arial, helvetica, sans-serif" size="4">PETSC ERROR: Could not locate a solver type for factorization type QR and matrix type mpiaij.</font><br></div><div><font face="arial, helvetica, sans-serif" size="4"><br></font></div><div><font face="arial, helvetica, sans-serif" size="4">Fuji</font></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Sep 26, 2022 at 10:25 AM Jose E. Roman <<a href="mailto:jroman@dsic.upv.es">jroman@dsic.upv.es</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">If the error message is "Could not locate a solver type for factorization type QR" then you should configure PETSc with --download-suitesparse<br>
<br>
Jose<br>
<br>
<br>
> El 26 sept 2022, a las 9:06, fujisan <<a href="mailto:fujisan43@gmail.com" target="_blank">fujisan43@gmail.com</a>> escribió:<br>
> <br>
> Thank you Pierre,<br>
> <br>
> I used PCNONE along with KSPLSQR and it worked.<br>
> But as for PCQR, it cannot be found. There is nothing about it in the documentation as well.<br>
> <br>
> Fuji<br>
> <br>
> On Wed, Sep 21, 2022 at 12:20 PM Pierre Jolivet <<a href="mailto:pierre@joliv.et" target="_blank">pierre@joliv.et</a>> wrote:<br>
> Yes, but you need to use a KSP that handles rectangular Mat, such as KSPLSQR (-ksp_type lsqr).<br>
> PCLU does not handle rectangular Pmat. The only PC that handle rectangular Pmat are PCQR, PCNONE.<br>
> If you supply the normal equations as the Pmat for LSQR, then you can use “standard” PC.<br>
> You can have a look at <a href="https://petsc.org/main/src/ksp/ksp/tutorials/ex27.c.html" rel="noreferrer" target="_blank">https://petsc.org/main/src/ksp/ksp/tutorials/ex27.c.html</a> that covers most of these cases.<br>
> <br>
> Thanks,<br>
> Pierre<br>
> <br>
> (sorry for the earlier answer sent wrongfully to petsc-maint, please discard the previous email)<br>
> <br>
>> On 21 Sep 2022, at 10:03 AM, fujisan <<a href="mailto:fujisan43@gmail.com" target="_blank">fujisan43@gmail.com</a>> wrote:<br>
>> <br>
>> I'm trying to solve Ax=b with a sparse rectangular matrix A (of size 33x17 in my test) using<br>
>> options '-ksp_type stcg -pc_type lu' on 1 or 2 cpus.<br>
>> <br>
>> And I always get an error saying "Incompatible vector local lengths" (see below).<br>
>> <br>
>> Here is the relevant lines of my code:<br>
>> <br>
>> program test<br>
>> ...<br>
>> ! Variable declarations<br>
>> <br>
>> PetscCallA(PetscInitialize(PETSC_NULL_CHARACTER,ierr))<br>
>> <br>
>> PetscCall(MatCreate(PETSC_COMM_WORLD,A,ierr))<br>
>> PetscCall(MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,m,n,ierr))<br>
>> PetscCall(MatSetType(A,MATMPIAIJ,ierr))<br>
>> PetscCall(MatSetFromOptions(A,ierr))<br>
>> PetscCall(MatSetUp(A,ierr))<br>
>> PetscCall(MatGetOwnershipRange(A,istart,iend,ierr))<br>
>> <br>
>> do irow=istart,iend-1<br>
>> ... Reading from file ...<br>
>> PetscCall(MatSetValues(A,1,irow,nzv,col,val,ADD_VALUES,ierr))<br>
>> ...<br>
>> enddo<br>
>> <br>
>> PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY,ierr))<br>
>> PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY,ierr))<br>
>> <br>
>> ! Creating vectors x and b<br>
>> PetscCallA(MatCreateVecs(A,x,b,ierr))<br>
>> <br>
>> ! Duplicating x in u.<br>
>> PetscCallA(VecDuplicate(x,u,ierr))<br>
>> <br>
>> ! u is used to calculate b<br>
>> PetscCallA(VecSet(u,1.0,ierr))<br>
>> <br>
>> PetscCallA(VecAssemblyBegin(u,ierr))<br>
>> PetscCallA(VecAssemblyEnd(u,ierr))<br>
>> <br>
>> ! Calculating Au = b<br>
>> PetscCallA(MatMult(A,u,b,ierr)) ! A.u = b<br>
>> <br>
>> PetscCallA(KSPSetType(ksp,KSPCG,ierr))<br>
>> <br>
>> PetscCallA(KSPSetOperators(ksp,A,A,ierr))<br>
>> <br>
>> PetscCallA(KSPSetFromOptions(ksp,ierr))<br>
>> <br>
>> ! Solving Ax = b, x unknown<br>
>> PetscCallA(KSPSolve(ksp,b,x,ierr))<br>
>> <br>
>> PetscCallA(VecDestroy(x,ierr))<br>
>> PetscCallA(VecDestroy(u,ierr))<br>
>> PetscCallA(VecDestroy(b,ierr))<br>
>> PetscCallA(MatDestroy(A,ierr))<br>
>> PetscCallA(KSPDestroy(ksp,ierr))<br>
>> <br>
>> call PetscFinalize(ierr)<br>
>> end program<br>
>> <br>
>> The code reads a sparse matrix from a binary file.<br>
>> I also output the sizes of matrix A and vectors b, x, u.<br>
>> They all seem consistent.<br>
>> <br>
>> What am I doing wrong?<br>
>> Is it possible to solve Ax=b with A rectangular?<br>
>> <br>
>> Thank you in advance for your help.<br>
>> Have a nice day.<br>
>> <br>
>> Fuji<br>
>> <br>
>> Matrix size : m= 33 n= 17 cpu size: 1<br>
>> Size of matrix A : 33 17<br>
>> Size of vector b : 33<br>
>> Size of vector x : 17<br>
>> Size of vector u : 17<br>
>> [0]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------<br>
>> [0]PETSC ERROR: Arguments are incompatible<br>
>> [0]PETSC ERROR: Incompatible vector local lengths parameter # 1 local size 33 != parameter # 2 local size 17<br>
>> [0]PETSC ERROR: See <a href="https://petsc.org/release/faq/" rel="noreferrer" target="_blank">https://petsc.org/release/faq/</a> for trouble shooting.<br>
>> [0]PETSC ERROR: Petsc Development GIT revision: v3.17.4-1341-g91b2b62a00 GIT Date: 2022-09-15 19:26:07 +0000<br>
>> [0]PETSC ERROR: ./bin/solve on a x86_64 named master by fujisan Tue Sep 20 16:56:37 2022<br>
>> [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<br>
>> [0]PETSC ERROR: #1 VecCopy() at /data/softs/petsc/src/vec/vec/interface/vector.c:1607<br>
>> [0]PETSC ERROR: #2 KSPSolve_BiCG() at /data/softs/petsc/src/ksp/ksp/impls/bicg/bicg.c:40<br>
>> [0]PETSC ERROR: #3 KSPSolve_Private() at /data/softs/petsc/src/ksp/ksp/interface/itfunc.c:877<br>
>> [0]PETSC ERROR: #4 KSPSolve() at /data/softs/petsc/src/ksp/ksp/interface/itfunc.c:1048<br>
>> [0]PETSC ERROR: #5 solve.F90:218<br>
>> Abort(75) on node 0 (rank 0 in comm 16): application called MPI_Abort(MPI_COMM_SELF, 75) - process 0<br>
>> <br>
> <br>
<br>
</blockquote></div>