source: inundation/pymetis/metis-4.0/CHANGES @ 3236

METIS 4.0.1, 11/29/98
------------------------------------------------------------------------------
This is mostly a bug-fix release

  - Fixed some bugs in the multi-constraint partitioning routines
  - Fixed some bugs in the volume-minimization routines



METIS 4.0.0, 9/20/98
------------------------------------------------------------------------------
METIS 4.0 contains a number of changes over the previous major release (ver 
3.0.x). Most of these changes are concentrated on the graph and mesh 
partitioning routines and they do not affect the sparse matrix re-ordering 
routines. Here is a list of the major changes:

  Multi-Constraint Partitioning
  -----------------------------
  METIS now includes partitioning routines that can be used to a partition
  a graph in the presence of multiple balancing constraints.

  Minimizing the Total Communication Volume
  -----------------------------------------
  METIS now includes partitioning routines whose objective is to minimize
  the total communication volume (as opposed to minimizing the edge-cut).

  Minimizing the Maximum Connectivity of the Subdomains
  -----------------------------------------------------
  The k-way partitioning routines in METIS can now directly minimize the number
  of adjacent subdomains. For most graphs corresponding to finite element 
  meshes, METIS is able to significantly reduce the maximum (and total) number of 
  adjacent subdomains.




METIS 3.0.6, 1/28/98
-------------------------------------------------------------------------------
  - Fixed some problems when too many partitions were asked, and each partition
    end up having 0 vertices
  - Fixed some bugs in the I/O routines
  - Added support for the g77 compiler under Linux


METIS 3.0.5, 12/22/97
-------------------------------------------------------------------------------
  - Fixed problems on 64-bit architectures (eg., -64 option on SGIs).
  - Added some options in Makefile.in


METIS 3.0.4, 12/1/97
-------------------------------------------------------------------------------
  Fixed a memory leak in the ordering code.


METIS 3.0.3, 11/5/97
-------------------------------------------------------------------------------
  This is mostly a bug-fix release with just a few additions

  Added functionality
    - Added support for quadrilateral elements.
    - Added a routine METIS_EstimateMemory that estimates the amount of
      memory that will be allocated by METIS. This is useful in determining
      if a problem can run on your system.
    - Added hooks to allow PARMETIS to use the orderings produced by METIS.
      This is hidden from the user but it will be used in the next release
      of PARMETIS.

  Bug-fixes
    - Fixed a bug related to memory allocation. This should somewhat reduce the 
      overall memory used by METIS.
    - Fixed some bugs in the 'graphchk' program in the case of weighted graphs.
    - Removed some code corresponding to unused options.
    - Fixed some minor bugs in the node-refinement code
      


-------------------------------------------------------------------------------
METIS 3.0 contains a number of changes over METIS 2.0.
The major changes are the following:

  General Changes
  ---------------
    1.  Added code to directly partition finite element meshes.

    2.  Added code to convert finite element meshes into graphs so they
        can be used by METIS.

    1.  The names, calling sequences, and options  of the routines in 
        METISlib have been changed.

    2.  Better support has been added for Fortran programs.

    3.  Eliminated the 'metis' program. The only way to tune METIS's
        behavior is to use METISlib.

    4.  Improved memory management. METIS should now only abort if truly
        there is no more memory left in the system.


  Graph Partitioning
  ------------------
    1.  Added partitioning routines that can be used to compute a partition 
        with prescribed partition weights. For example, they can be used to 
        compute a 3-way partition such that partition 1 has 50% of the weight, 
        partition 2 has 20% of the way, and partition 3 has 30% of the weight. 

    2.  Improved the speed of the k-way partitioning algorithm (kmetis). The
        new code has better cache locality which dramatically improves the 
        speed for large graphs. A factor of 4 speedup can be obtained for
        certain graphs. METIS can now partition a 4 million node graph
        in well under a minute on a MIPS R10000.

    3.  Eliminated some of the options that were seldom used. 
  

  Fill-Reducing Orderings
  ----------------------
    1.  Added a node based ordering code `onmetis' that greatly improves 
        ordering quality.

    2.  Improved the quality of the orderings produced by the original
        edge-based ordering code (it is now called 'oemetis').

    3.  METIS can now analyze the graph and try to compress together 
        nodes with identical sparsity pattern. For some problems, this 
        significantly reduces ordering time 

    4.  METIS can now prune dense columns prior to ordering. This can be
        helpful for LP matrices.
        

  Mesh Partitioning
  -----------------
    1.  METIS can now directly partition the element node array of finite
        element meshes. It produces two partitioning vectors. One for the
        elements and one for the nodes. METIS supports the following 
        elements: triangles, tetrahedra, hexahedra


  Mesh-To-Graph Conversion Routines
  ---------------------------------
    1.  METIS now includes a number of mesh conversion functions that can 
        be used to create the dual and nodal graphs directly from the 
        element connectivity arrays. These are highly optimized routines.