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Nested Dissection by Scotch

Nested Dissection is a popular method to compute fill-reducing orderings for graphs and sparse matrices. It can also be used for other ordering purposes. The algorithm recursively finds a separator (bisector) in a graph, orders the nodes in the two subsets first, and nodes in the separator last.

Scotch is a library for ordering and partitioning, developed at LaBRI in Bordeaux, France. PT-Scotch is the parallel module in Scotch. (We use the names Scotch and PT-Scotch interchangeably.) Scotch is a third-party library in Zoltan and should be obtained separately from the Scotch web site. Currently, Zoltan supports version 5.1 of Scotch, compiled with the support of PT-Scotch and int coding for vertices, not long (on architectures where sizeof(int) != sizeof(long)).

If the parameter ORDER_TYPE is set to LOCAL, it's the sequential version of Scotch which is called, not the parallel.

Order_Method String: SCOTCH
Parameters:
   SCOTCH_METHOD For now, always set to NODEND
   SCOTCH_STRAT The Scotch strategy string; see the Scotch documentation.
   SCOTCH_STRAT_FILE A file that contains an arbitrary long Scotch strategy string; see the Scotch documentation.
Required Query Functions:
ZOLTAN_NUM_OBJ_FN
ZOLTAN_OBJ_LIST_FN
ZOLTAN_NUM_EDGES_MULTI_F N or ZOLTAN_NUM_EDGES_FN
ZOLTAN_EDGE_LIST_MULTI_F N or ZOLTAN_EDGE_LIST_FN


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