Hello !
Here is my problem. I need to use the cbc.block package for my python code (I need block-structure matrix), but I don't know how to apply my boundary condition (Dirichlet boundary conditions, basically non-slip conditions). Let me explain:
I downloaded the last version of cbc.block from: https://bitbucket.org/fenics-apps/cbc.bloI ck/overview. I first tried to run some demo, mixedpoisson.py and biot.py for example. However, I have a problem with the block_symmetric_assemble and block_assemble functions. Here is the error I obtain :
Traceback (most recent call last):
File "mixedpoisson.py", line 97, in
[a21, 0 ]], bcs=bcs)
File "/usr/local/lib/python2.7/dist-packages/block/block_assemble.py", line 35, in block_symmetric_assemble
symm[i,j], asymm[i,j] = _symmetric_assemble(forms[i,j], row_bcs=bcs[i], col_bcs=bcs[j])
File "/usr/local/lib/python2.7/dist-packages/block/block_assemble.py", line 79, in _symmetric_assemble
from dolfin import symmetric_assemble
ImportError: cannot import name symmetric_assemble
I suspect an incompatibility between the versions of FEniCS/cbc.block (I have dolfin-1.2.0). I understood that "symmetric_assemble" does no longer exist in the Python interface, sp obviously it won't work.
Consequently, I downloaded a previous version of cbc.block (1.0.1), where I can use bc = block_bc([...]) (with inside my boundary conditions defined with DirichletBC) and bc.apply(A, b) to apply my boundary conditions (block_bc is not available in the last version of cbc.block). I previously assemble my blocks and build my block matrix with: A = block_mat([...]) and the RHS: b = block_vec([...]).
Obviously, it's not the best way to do it (some of the demo for example still don't work), but I don't know how to apply boundary conditions with the newest version of cbc.block.
On top of that, I have an other error which I don't know how to solve:
Calculated signs of diagonal blocks:[1, None, 1]
Traceback (most recent call last):
File "block_stokes_1.py", line 93, in
bc.apply(A, b, save_A=True)
File "/usr/local/lib/python2.7/dist-packages/block/block_bc.py", line 41, in apply
self.apply_matvec(A, b, symmetric)
File "/usr/local/lib/python2.7/dist-packages/block/block_bc.py", line 87, in apply_matvec
bc.zero_columns(A[j,i], b[j])
TypeError: in method 'DirichletBC_zero_columns', argument 2 of type 'dolfin::GenericMatrix &'
I had an idea from https://lists.launchpad.net/cbc.block/msg00018.html, but even with that, it still doesn't work.So now, I'm lost ! Anyone can help me with that ?
Thanks in advance for your time (sorry for the huge question...),
Coraline
PS: I install FEniCS via dorsal, so I have dolfin-1.2.0
Python 2.7.3
