Thank You for the side note
I have linked my mesh (a .msh file) below. Code has been edited in the post to import modules
GDrive link for .msh file
I tried running the again, and now I get a different error
Error: error code 73
[0] KSPSolve() at /home/conda/feedstock_root/build_artifacts/petsc_1656827302664/work/src/ksp/ksp/interface/itfunc.c:1078
[0] KSPSolve_Private() at /home/conda/feedstock_root/build_artifacts/petsc_1656827302664/work/src/ksp/ksp/interface/itfunc.c:843
[0] KSPSetUp() at /home/conda/feedstock_root/build_artifacts/petsc_1656827302664/work/src/ksp/ksp/interface/itfunc.c:407
[0] PCSetUp() at /home/conda/feedstock_root/build_artifacts/petsc_1656827302664/work/src/ksp/pc/interface/precon.c:990
[0] PCSetUp_ILU() at /home/conda/feedstock_root/build_artifacts/petsc_1656827302664/work/src/ksp/pc/impls/factor/ilu/ilu.c:141
[0] MatILUFactorSymbolic() at /home/conda/feedstock_root/build_artifacts/petsc_1656827302664/work/src/mat/interface/matrix.c:6697
[0] MatILUFactorSymbolic_SeqAIJ() at /home/conda/feedstock_root/build_artifacts/petsc_1656827302664/work/src/mat/impls/aij/seq/aijfact.c:1675
[0] Object is in wrong state
[0] Matrix is missing diagonal entry 0
I looked it up and found this, where you have instructed to create a ‘submesh’
I wish to get the solution over the whole domain, which is divided into 2 subdomains. Is it required for me to create a submesh . (Since this step was not required in dolfin).