Matrix Entry that belongs to two partitions

[Franz Pichler]

Hello,
we are facing an issue with matrix entries that should connect two nodes that might possibly be part of different partitions.
My questions are:
1) Generally, is the whole system matrix accesible in parallel?
In other words can i somehow acces entry i,j where i is the global row of a node (its test function) belonging to partition 1 and j is the global column of a node (its base function) belonging to partition 2.
or are only the parts saved that form a square matrix connected to all the nodes of the partition?

2)if not is there a way to assure that two boundaries are in one partition? These to boundaries are both sets of many small boundaries that have partner boundaries and i have to connect them. so both bcs have to be in the same partition

3) could i realize what i ask in 2 by simply adding all the nodes to the shared nodes file somehow in a preprocessing step?

i hope these questions make sense to someone,


best regards

Franz

[raback]

Hi

1) No. On shared nodes are accessible.

2) Use the -connect flag in ElmerGrid where the flag should be followed by all the BC indeces that you want to join so that they will be in the same partition. If you have several flags you can have several connected groups.

-Peter