openfoam/applications/utilities/parallelProcessing/decompositionMethods/parMetisDecomp/ParMetis-3.1/CHANGES

Changes in version 3.1
- The mesh partitioning and dual creation routines have changed to support mixed
  element meshes.

- The parmetis.h header file has been restructured and is now C++ friendly.

- Fortran bindings/renamings for various routines have been added.

- A number of bugs have been fixed.
  - tpwgts are now respected for small graphs.
  - fixed various divide by zero errors.
  - removed dependency on the old drand48() routines.
  - fixed some memory leaks.



Changes in version 3.0

- The names and calling sequence of all the routines have changed due to expanded
  functionality that has been provided in this release. However, the 2.0 API calls 
  have been mapped to the new routines. However, the expanded functionality provided 
  with this release is only available by using the new calling sequences.

- The four adaptive repartitioning routines: 
    ParMETIS_RepartLDiffusion, 
    ParMETIS_RepartGDiffusion,
    ParMETIS_RepartRemap, and
    ParMETIS_RepartMLRemap,
  have been replaced by a single routine called ParMETIS_V3_AdpativeRepart that 
  implements a unified repartitioning algorithm which combines the best features 
  of the previous routines.

- Multiple vertex weights/balance constraints are supported for most of the
  routines. This allows ParMETIS to be used to partition graphs for multi-phase
  and multi-physics simulations.

- In order to optimize partitionings for specific heterogeneous computing 
  architectures, it is now possible to specify the target sub-domain weights 
  for each of the sub-domains and for each balance constraint. This feature, 
  for example, allows the user to compute a partitioning in which one of the 
  sub-domains is twice the size of all of the others.

- The number of sub-domains has been de-coupled from the number of processors
  in both the static and the adaptive partitioning schemes. Hence, it is now
  possible to use the parallel partitioning and repartitioning algorithms
  to compute a k-way partitioning independent of the number of processors
  that are used. Note that Version 2.0 provided this functionality for the 
  static partitioning schemes only.

- Routines are provided for both directly partitioning a finite element mesh, 
  and for constructing the dual graph of a mesh in parallel.



Changes in version 2.0

- Changed the names and calling sequences of all the routines to make it 
  easier to use ParMETIS with Fortran. 

- Improved the performance of the diffusive adaptive repartitioning 
  algorithms.

- Added a new set of adaptive repartitioning routines that are based on the
  remapping paradigm. These routines are called ParMETIS_RepartRemap and
  ParMETIS_RepartMLRemap

- The number of partitions has been de-coupled from the number of processors.
  You can now use the parallel partitioning algorithms to compute a k-way
  partitioning independent of the number of processors that you use.

- The partitioning and ordering algorithms in ParMETIS now utilize various
  portions of the serial METIS library. As a result of this, the quality
  of the produced partitionings and orderings have been improved. 
  Remember to link your code with both libmetis.a and libparmetis.a


Changes in version 1.0

- Added partitioning routines that take advantage of coordinate information.
  These routines are based on space-filling curves and they are used to 
  quickly compute a initial distribution for PARKMETIS.
  A total of three routines have been added called PARGKMETIS, PARGRMETIS,
  and PARGMETIS

- Added a fill-reducing ordering routine that is based on multilevel nested 
  dissection. This is similar to the ordering routine in the serial Metis 
  with the difference that is directly computes and refines vertex 
  separators. The new routine is called PAROMETIS and returns the new ordering
  of the local nodes plus a vector describing the sizes of the various
  separators that form the elimination tree.  

- Changed the calling sequence again! I found it awkward to require that
  communicators and other scalar quantities being passed by reference.

- Fixed a number of memory leaks.



Changes in version 0.3

- Incorporated parallel multilevel diffusion algorithms for repartitioning
  adaptively refined meshes. Two routines have been added for this purpose:
  PARUAMETIS that performs undirected multilevel diffusion
  PARDAMETIS that performs directed multilevel diffusion

- Changed the names and calling sequences of the parallel partitioning
  and refinement algorithms. Now they are called PARKMETIS for the
  k-way partitioning and PARRMETIS for the k-way refinement.
  Also the calling sequence has been changed slightly to make ParMETIS
  Fortran callable.

- Added an additional option for selecting the algorithm for initial
  partitioning at the coarsest graph. Now you have the choice of selecting
  either a serial or a parallel algorithm. The parallel initial partitioning
  speeds up the algorithm especially for large number of processors.
  NOTE that the parallel initial partitioning works only for partitions that
  are power of two. If you want partitions that are not power of two you must
  use the old serial initial partitioning option.

- Fixed some bugs in the initial partitioning code.

- Made parallel k-way refinement more robust by randomly ordering the
  processors at each phase


Changes in version 0.2

- A complete reworking of the primary algorithms. The performance
  of the code has improved considerably. Over 30% on 128 processor
  Cray T3D. Improvement should be higher on machines with high
  latencies.

  Here are some performance numbers on T3D using Cray's MPI
  for 2 graphs, mdual (0.25M vertices) and mdual2 (1.0M vertices)

	       16PEs 	32PEs	64PEs	128PEs
  mdual		4.07	2.97	2.82	
  mdual2       15.02	8.89	6.12	5.75

- The quality of the produced partitions has been improved.
- Added options[2] to specify C or Fortran style numbering.