[Libmesh-users] Bug in dof_map.C

[LengWei <len...@gm...>]

Hi,


I'm trying to implement the pressure convection-diffusion preconditioner
for
steady-state Navier-stokes equaions.

I am not sure if I am doing it in an approperate way... Here is the outline:
In general, use the pestc precondition shell matrix, specificly,
* build subblock Matrix manually
* extract subvector form vector, namely (u,v,w) and p from x, using
variable_first_local_dof
* create some solver to perform the inverse operation of matrix, or mat
vec multiplication

Is there a more decent way to do this?

BTW, there is a bug in dof_map.C, which I check out from svn,
around line 915,

>> if (var == n_vars-1)
_var_first_local_df.push_back(next_free_dof);

_var_first_local_df[nvar+1] record the offset of vars, like
[u_begin, v_begin, w_begin, p_begin, p_end],
but without "if (var == n_vars-1)", it becomes
[u_begin, u_end, v_begin, v_end, w_begin, w_end, p_begin, p_end]



Regards,


Lengwei