If I want to get the residual vector from a SNES, what is the correct calling
order?
Currently, I have
VecDuplicate(U,&F);
SNESSetFunction(snes, F, form_function, ctx);
SNESSolve(snes, NULL, U);
SNESGetFunction(snes,&F,NULL,NULL);
VecDestroy(&U);
VecDestroy(&F);
But this generates an error,
[0]PETSC ERROR: --------------------- Error Message
--------------------------------------------------------------
[0]PETSC ERROR: Invalid argument
[0]PETSC ERROR: Wrong type of object: Parameter # 1
[0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for
trouble shooting.
[0]PETSC ERROR: Petsc Release Version 3.6.1, unknown
[0]PETSC ERROR: ./blowup_refine on a arch-darwin-c-debug named gs_air by gideon
Thu Sep 10 11:36:10 2015
[0]PETSC ERROR: Configure options --download-mpich=yes
--download-suitesparse=yes --download-superlu=yes --download-superlu_dist=yes
--download-mumps=yes --download-sprng=yes --with-cxx=clang++ --with-cc=clang
--with-fc=gfortran --download-metis=yes --download-parmetis=yes
--download-scalapack=yes
[0]PETSC ERROR: #1 VecDestroy() line 424 in
/opt/petsc/src/vec/vec/interface/vector.c
-gideon
