[petsc-users] Index set does not match blocks

[Smith, Barry F.]

   For BAIJ matrices with ASM preconditioner the index sets that define the ASM blocks must contain all the points in a block or none of them. The code is detecting this is not the case; I don't know why this would be different between 3.8 and 3.6

   You can use the option -start_in_debugger and put a break point in MatCreateSubMatrix_SeqBAIJ() then do 

call ISView(isrow,0)

and look at the indices printed. Do the sets of indices match the block size? 

How do you set the ASM blocks for your code?  They must be not set correctly when bs > 1.


   Barry

Perhaps in 3.6 we did less error checking and so did not detect the error in that case.



> On Apr 7, 2018, at 12:24 AM, Rongliang Chen <rongliang.chan at gmail.com> wrote:
> 
> Hello everyone,
> 
> 
> I updated my code from petsc-3.6 to petsc-3.8 and got the following error. But it works well if I set the block size to be 1. I am solving an unstructured mesh problem. Any suggestions for debugging this are welcome. Thanks.
> 
> 
> Best,
> 
> Rongliang
> 
> 
> [0]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------
> [0]PETSC ERROR: Nonconforming object sizes
> [0]PETSC ERROR: Index set does not match blocks
> [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for trouble shooting.
> [0]PETSC ERROR: Petsc Release Version 3.8.4, Mar, 24, 2018
> [0]PETSC ERROR: ./HiBflow on a 64bit-debug named rongliang-chen by rlchen Sat Apr  7 13:14:20 2018
> [0]PETSC ERROR: Configure options --download-mpich --download-blacs --download-scalapack --download-metis --download-parmetis --download-exodusii --download-netcdf --download-hdf5 --with-debugging=1 --download-fblaslapack --download-ctetgen --with-64-bit-indices
> [0]PETSC ERROR: #1 MatCreateSubMatrix_SeqBAIJ() line 184 in /home/rlchen/soft/petsc-3.8.4/src/mat/impls/baij/seq/baij2.c
> [0]PETSC ERROR: #2 MatCreateSubMatrices_SeqBAIJ() line 264 in /home/rlchen/soft/petsc-3.8.4/src/mat/impls/baij/seq/baij2.c
> [0]PETSC ERROR: #3 MatCreateSubMatrices() line 6764 in /home/rlchen/soft/petsc-3.8.4/src/mat/interface/matrix.c
> [0]PETSC ERROR: #4 PCSetUp_ASM() line 326 in /home/rlchen/soft/petsc-3.8.4/src/ksp/pc/impls/asm/asm.c
> [0]PETSC ERROR: #5 PCSetUp() line 924 in /home/rlchen/soft/petsc-3.8.4/src/ksp/pc/interface/precon.c
> [0]PETSC ERROR: #6 KSPSetUp() line 381 in /home/rlchen/soft/petsc-3.8.4/src/ksp/ksp/interface/itfunc.c
> [0]PETSC ERROR: #7 KSPSolve() line 612 in /home/rlchen/soft/petsc-3.8.4/src/ksp/ksp/interface/itfunc.c
> [0]PETSC ERROR: #8 SNESSolve_NEWTONLS() line 224 in /home/rlchen/soft/petsc-3.8.4/src/snes/impls/ls/ls.c
> [0]PETSC ERROR: #9 SNESSolve() line 4131 in /home/rlchen/soft/petsc-3.8.4/src/snes/interface/snes.c
> [0]PETSC ERROR: #10 TimeStep() line 1751 in /home/rlchen/soft/3D_fluid/3DBloodFlow/Cerebral/Twolevel-3.8/HiBflow.c
> [0]PETSC ERROR: #11 SolveTimeDependent() line 1315 in /home/rlchen/soft/3D_fluid/3DBloodFlow/Cerebral/Twolevel-3.8/HiBflow.c
> [0]PETSC ERROR: #12 JoabCtxSolve() line 263 in /home/rlchen/soft/3D_fluid/3DBloodFlow/Cerebral/Twolevel-3.8/HiBflow.c
> [0]PETSC ERROR: #13 main() line 158 in /home/rlchen/soft/3D_fluid/3DBloodFlow/Cerebral/Twolevel-3.8/HiBflow.c
>