Hi, I now get the following error File "compressible_stratified.py", line 137, in <module> print A.M.handle.getValues(1,1) File "PETSc/Mat.pyx", line 738, in petsc4py.PETSc.Mat.getValues (src/petsc4py.PETSc.c:121949) File "PETSc/petscmat.pxi", line 919, in petsc4py.PETSc.matgetvalues (src/petsc4py.PETSc.c:29292) petsc4py.PETSc.Error: error code 56 [0] MatGetValues() line 1845 in /tmp/pip-v0eIT6-build/src/mat/interface/matrix.c [0] No support for this operation for this object type [0] Mat type nest ________________________________ From: firedrake-bounces@imperial.ac.uk <firedrake-bounces@imperial.ac.uk> on behalf of Justin Chang <jychang48@gmail.com> Sent: 24 August 2016 19:18:54 To: firedrake@imperial.ac.uk Subject: Re: [firedrake] Accessing values of a block matrix system Use print A.M.handle.getValues(1,1) On Wednesday, August 24, 2016, William Booker <scwb@leeds.ac.uk<mailto:scwb@leeds.ac.uk>> wrote: Dear Firedrakers, I'm trying to compare the matrices I get from matlab to the ones generated in Firedrake, but I've run into some issues: A = assemble(a, nest=True) print A.getValues(1,1) gives me File "compressible_stratified.py", line 137, in <module> print A.getValues(1,1) AttributeError: 'Matrix' object has no attribute 'getValues' How would I fix this ? Regards Will