[Libmesh-users] Variables numbering (Bloc Matrix)

[Buffat M. <bu...@uf...>]

Hi,
 congratulations for the great job you're doing.
 I am implementing FV formulation using the MONOMIAL  element for CFD 
(compressible). I am solving a coupled system of 5 equations.
As I understand, the dof variable numbering in libmesh is one variable after 
the other: ie.  for 5 variables RHO, U,V,W, E  per element the dof numbering 
is (for N elements):
R1 ..... RN U1 ... UN V1...VN  W1...WN E1 ... EN
For my problem, it is not optimal: i.e. a block numbering is more appropriate 
i.e.
R1 U1 V1 W1 E1  R2 U2 V2 W2 E2 ...... RN UN VN WN EN
as it allows the use of the sparse bloc matrix structure of PETSC with 
MatCreateMPIBAIJ()

Is it possible to change the dof variable numbering in libmesh without too 
much effort. I have a good knowledge of  OOP and C++. 

I have also found a BUG in petsc_vector.h for the operator()(unsigned int i)
the patch is attached.
Thanks,
	Marc


-- 
Marc BUFFAT, Pr. Universite Claude Bernard LYON I 
tel:  (33) 04/72/43/11/02 (UCBL)
fax:  (33) 04/72/44/80/54
bu...@uf... | http://p2chpd-cluster.univ-lyon1.fr