Order of variables

[uwe]

Hi Elmer Team,

when coding a solver for a coupled problem i put a statement like

Code: Select all

  Variable = STRING Field[var1:1 var2:1]
  Variable DOFS = 2
  Procedure = "MyLibrary/mySolve" "mySolve"

in the sif file.

When doing the element matrix assembly the order of the variable in the solution vector matters.
I guessed it to be blockwise (var1_node1, var1_node2, .... var1_node_n, var2_node1, var2_node2, ..... var2_node_n)

Is this correct?

In viewtopic.php?f=3&t=2206 you mentioned a Block keyword for the nonlinear system iterative methode. It's not yet in the documentation(ElmerSolver manual March,3 2012), right?

Thx and a good night,
Uwe

[raback]

Hi

The order is actually "var1_node1, var2_node1, .... var1_node_n, var2_node_n. This is probably mainly for historical reasons as it minimizes bandwidth. It could perhaps also better favour use of cache in matrix-vector products. It's hard to say as it hasn't been used.

The "block" solution strategy is not documented. There are a few tests for it though starting with "Block".

-Peter