Distillating knowledge about SCOTCH

The design of the Scotch library for static mapping, graph partitioning and sparse matrix ordering is highly modular, so as to allow users and potential contributors to tweak it and add easily new static mapping, graph bipartitioning, vertex separation or graph ordering methods to match their particular needs. The purpose of this tutorial is twofold. It will start with a description of the interface of Scotch, presenting its visible objects and data structures. Then, we will step into the API mirror and have a look at the inside: the internal representation of graphs, mappings and orderings, and the basic sequential and parallel building blocks: graph induction, graph coarsening which can be re-used by third-party software. As an example, we will show how to add a simple genetic algorithm routine to the graph bipartitioning methods

PT-Scotch: A tool for efficient parallel graph ordering

The parallel ordering of large graphs is a difficult problem, because on the one hand minimum degree algorithms do not parallelize well, and on the other hand the obtainment of high quality orderings with the nested dissection algorithm requires efficient graph bipartitioning heuristics, the best sequential implementations of which are also hard to parallelize. This paper presents a set of algorithms, implemented in the PT-Scotch software package, which allows one to order large graphs in parallel, yielding orderings the quality of which is only slightly worse than the one of state-of-the-art sequential algorithms. Our implementation uses the classical nested dissection approach but relies on several novel features to solve the parallel graph bipartitioning problem. Thanks to these improvements, PT-Scotch produces consistently better orderings than ParMeTiS on large numbers of processors

Scotch and libScotch 5.1 User's Guide

127 pagesUser's manualThis document describes the capabilities and operations of Scotch and libScotch, a software package and a software library devoted to static mapping, partitioning, and sparse matrix block ordering of graphs and meshes/hypergraphs. It gives brief descriptions of the algorithms, details the input/output formats, instructions for use, installation procedures, and provides a number of examples. Scotch is distributed as free/libre software, and has been designed such that new partitioning or ordering methods can be added in a straightforward manner. It can therefore be used as a testbed for the easy and quick coding and testing of such new methods, and may also be redistributed, as a library, along with third-party software that makes use of it, either in its original or in updated forms

Recent Advances in Graph Partitioning

We survey recent trends in practical algorithms for balanced graph partitioning together with applications and future research directions

PT-Scotch and libScotch 5.0 User's Guide

54 pagesUser's ManualThis document describes the capabilities and operations of PT-Scotch and libScotch, a software package and a software library which compute parallel sparse matrix block orderings of graphs. It gives brief descriptions of the algorithms, details the input/output formats, instructions for use, installation procedures, and provides a number of examples. PT-Scotch is distributed as free/libre software, and has been designed such that new partitioning or ordering methods can be added in a straightforward manner. It can therefore be used as a testbed for the easy and quick coding and testing of such new methods, and may also be redistributed, as a library, along with third-party software that makes use of it, either in its original or in updated forms