[Trilinos-Users] Question about inserting a row not owned by a processor.

[M. Scot Breitenfeld]

Greetings,

I'll try to explain a simplified version of my situation the best that I
can. Lets say I have a line discretized as follows:

       Proc 0            |    Proc 1    
      o------o------o---|---o-----o-----o
      1       2      3          4     5      6  (global number)

where o are nodes (there are no elements for this method) and there is
only 1 d.o.f at each node

For Processor 0 I register: as my global node list: 1, 2, 3, 4
                                           as the row list: 1, 2, 3, 4
                                           as my owned node list: 1, 2, 3

       Proc 0
      o------o------o---|---o
      1       2        3       4 (global number)
        1         2          3         4   (rows in global list)

For Processor 1 I register: as my global node list: 4, 5, 6, 3
                                           as the row list: 4, 5, 6, 3
                                           as my owned node list: 4, 5, 6

      Proc 1    
      o---|---o------o------o
      3        4       5       6 (global number)
        3         4          5         6   (rows in global list)

Now up to this point it works fine in parallel. But for my method I have
something like this:

row 1:  (T12-T21)*V2+(T13-T31)*V3+(T14-T41)*V4
row 2:  (T21-T12)*V2+(T23-T32)*V3+(T24-T42)*V4
row 3:  (T31-T13)*V2+(T34-T43)*V3
row 4:  (T41-T14)*V2+(T45-T54)*V3+(T34-T43)*V4
....

T12, for example, means node 1 is influenced by node 2; meaning
processor 0 will calculate T12, T13, T14 which is fine. But T14 also
needs to be subtracted from row 4. The problem is row 4 (node 4) is not
owned by processor 0, it's on processor 1. When I use InsertGlobalValues
to insert the values in row 4 on processor 0 it will return an error. Do
I have to write mpi code to pass the T14 matrix to processor one to
insert into row 4, or is there a routine that I can use instead, or
maybe I'm missing something.

Thanks,
Scot