[petsc-users] Question on local vec to global vec for dof > 1

[Danyang Su]

Hi All,

I have a 1D transient flow problem (1 dof) coupled with energy balance 
(1 dof), so the total dof per node is 2.

The whole domain has 10 nodes in z direction.

The program runs well with 1 processor but failed in 2 processors. The 
matrix is the same for 1 processor and 2 processor but the rhs are 
different.

The following is used to set the rhs value.

call VecGetArrayF90(x_vec_loc, vecpointer, ierr)
vecpointer = (calculate the rhs value here)
call VecRestoreArrayF90(x_vec_loc,vecpointer,ierr)
call DMLocalToGlobalBegin(da,x_vec_loc,INSERT_VALUES, x_vec_gbl,ierr)
call DMLocalToGlobalEnd(da,x_vec_loc,INSERT_VALUES, x_vec_gbl,ierr)

*Vecview  Correct * *Vecview Wrong*
dof     local node           Process [0] _Process [0] _ /_Process [0] _/
1            1              1.395982780116148E-021 
1.39598e-021                 1.39598e-021
1            2              0.000000000000000E+000 
0                                       0
1            3              0.000000000000000E+000 
0                                       0
1            4              5.642372883946980E-037 
5.64237e-037                 5.64237e-037
1            5              0.000000000000000E+000 
0                                       0
1            6 -1.395982780116148E-021 -7.52316e-037                
-1.39598e-021 Line A
2            1 0.000000000000000E+000 7.52316e-037                 0
2            2 0.000000000000000E+000 0 0
2            3 0.000000000000000E+000 1.68459e-016 0
2            4 4.814824860968090E-035 0.1296 4.81482e-035
2            5 0.000000000000000E+000 _/Process [1]/_ Line B
2            6 -1.371273884908092E-019 0 
7.52316e-037                       Line C
0               0
                                        Process [1] 0 1.68459e-016
1            1 1.395982780116148E-021 4.81482e-035 
0.1296                                     Line D
1            2 -7.523163845262640E-037 0 
1.37127e-019                         Line E
1            3 7.523163845262640E-037 -7.22224e-035                
-7.22224e-035
1            4 0.000000000000000E+000 7.22224e-035                 
7.22224e-035
1            5 1.684590875336239E-016 
0                                       0
1            6 0.129600000000000          
128623                            128623
2            1 1.371273884908092E-019 
0                                       0 Line F
2            2             -7.222237291452134E-035
2            3              7.222237291452134E-035
2            4              0.000000000000000E+000
2            5               128623.169844761
2            6              0.000000000000000E+000

The red line (Line A, C, D and F) is the ghost values for 2 subdomains, 
but when run with 2 processor, the program treates Line B, C, D, and E 
as ghost values.
*How can I handle this kind of local vector to global vector assembly?*

*In fact, the codes can work if the dof and local node is as follows.*
dof     local node
1            1
2            1
1            2
2            2
1            3
2            3

Thanks and regards,

Danyang
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