Dear PETSc dev team, I am implementing SLEPc interval option using shell matrix as follows:
EPSGetST(eps, &st); STSetType(st, STSINVERT); STGetKSP(st, &ksp); KSPSetOperators(ksp, A, A); KSPSetType(ksp, KSPPREONLY); KSPGetPC(ksp, &pc); KSPGetPC(ksp, &pc) MatSetOption(A, MAT_SPD, PETSC_TRUE); PCSetType(pc, PCSHELL); PCShellSetContext(pc, &appCtx); PCShellSetApply(pc, applyPreconditioner); PetscObjectComposeFunction((PetscObject)pc,"PCFactorGetZeroPivot_C",PCFactorGetZeroPivot_C); When I run it, I get the following error. Any idea what I did wrong? Thanks a lot for your help. [0]PETSC ERROR: No support for this operation for this object type [0]PETSC ERROR: PC type does not support getting factor matrix [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for trouble shooting. [0]PETSC ERROR: Petsc Release Version 3.11.3, Jun, 26, 2019 [0]PETSC ERROR: Unknown Name on a arch-starccmplus_serial_real named pl2usbvu0037pc.net.plm.eds.com by cd4hhv Thu Nov 18 21:11:45 2021 Number of iterations of the method: 0 [0]PETSC ERROR: Configure options --with-x=0 --with-fc=0 --with-debugging=1 --with-blaslapack-dir=/u/cd4hhv/dev2/mkl/2017.2-cda-001/linux/lib/intel64/../.. --with-mpi=0 -CFLAGS=-g -CXXFLAGS=-g --with-clean=1 --force --with-scalar-type=real [0]PETSC ERROR: #1 PCFactorGetMatrix() line 1332 in ../../../petsc/src/ksp/pc/interface/precon.c [0]PETSC ERROR: #2 EPSSliceGetInertia() line 340 in ../../../slepc/src/eps/impls/krylov/krylovschur/ks-slice.c [0]PETSC ERROR: #3 EPSSetUp_KrylovSchur_Slice() line 467 in ../../../slepc/src/eps/impls/krylov/krylovschur/ks-slice.c [0]PETSC ERROR: #4 EPSSetUp_KrylovSchur() line 146 in ../../../slepc/src/eps/impls/krylov/krylovschur/krylovschur.c [0]PETSC ERROR: #5 EPSSetUp() line 173 in ../../../slepc/src/eps/interface/epssetup.c Solution method: krylovschur [0]PETSC ERROR: #6 EPSSliceGetEPS() line 306 in ../../../slepc/src/eps/impls/krylov/krylovschur/ks-slice.c [0]PETSC ERROR: #7 EPSSetUp_KrylovSchur_Slice() line 416 in ../../../slepc/src/eps/impls/krylov/krylovschur/ks-slice.c [0]PETSC ERROR: #8 EPSSetUp_KrylovSchur() line 146 in ../../../slepc/src/eps/impls/krylov/krylovschur/krylovschur.c [0]PETSC ERROR: #9 EPSSetUp() line 173 in ../../../slepc/src/eps/interface/epssetup.c
