METIS API wrapper for Ruby

* Author

 - Masahiro TANAKA

* Requirement

 - METIS ver 5.0pre2
 - tested with Ruby 1.9.2 and gcc 4.5.1

* Install

  $ ruby setup.rb config
  $ ruby setup.rb setup
  # ruby setup.rb install

 Note: The first step above includes steps to download and compile
       METIS sources.  If you want do it manually, execute the
       following commands.

  $ wget http://glaros.dtc.umn.edu/gkhome/fetch/sw/metis/metis-5.0pre2.tar.gz
  $ tar xvzf metis-5.0pre2.tar.gz
  $ patch -p0 < patch-metis-5.0pre2
  $ cd metis-5.0pre2
  $ make all usegdb=1 usefpic=1


* Call sequence

 - Metis.part_graph( xadj, adjncy, [vertex_wgt|nil],
   		     [adj_wgt|nil], [n_part|part_wgt] )

    Partition a Graph into n-parts to minimize the edgecut.
    If the last argument is a Numeric, the graph is partitioned into
    equal-sized parts.
    If the last argument is an Array, the graph is partitioned into
    weighted parts.
    If n_part <= 8, it uses the multilevel recursive bisection method.
    If n_part >  8, it uses the multilevel k-way partitioning algorithm.
    See METIS manual for the graph data structure.

 - Metis.part_graph_recursive( xadj, adjncy, [vertex_wgt|nil],
   			       [adj_wgt|nil], [n_part|part_wgt] )

    Same as the part_graph method except it always uses the multilevel
    recursive bisection method.

 - Metis.part_graph_kway( xadj, adjncy, [vertex_wgt|nil],
   			  [adj_wgt|nil], [n_part|part_wgt] )

    Same as the part_graph method except it always uses the multilevel k-way
    partitioning algorithm.


 - Metis.mc_part_graph( ncon, xadj, adjncy, [vertex_wgt|nil],
   		        [adj_wgt|nil], [ubvec|nil], [n_part|part_wgt] )

    Multi-Constraint Partitioning a Graph into n-parts to minimize the
    edgecut.
    If the last argument is a Numeric, the graph is partitioned into
    equal-sized parts.
    If the last argument is an Array, the graph is partitioned into
    weighted parts.
    If n_part <= 8, it uses the multilevel recursive bisection method.
    If n_part >  8, it uses the multilevel k-way partitioning algorithm.
    See METIS manual for the graph data structure.

 - Metis.mc_part_graph_recursive( ncon, xadj, adjncy, [vertex_wgt|nil],
   		        [adj_wgt|nil], [n_part|part_wgt] )

    Same as the mc_part_graph method except it always uses the
    multilevel recursive bisection method.

 - Metis.mc_part_graph_kway( ncon, xadj, adjncy, [vertex_wgt|nil],
   		        [adj_wgt|nil], [ubvec|nil], [n_part|part_wgt] )

    Same as the mc_part_graph method except it always uses the
    multilevel k-way partitioning algorithm.


* METIS Reference:
    "A Fast and Highly Quality Multilevel Scheme for Partitioning Irregular Graphs".
    George Karypis and Vipin Kumar. SIAM Journal on Scientific Computing,
    Vol. 20, No. 1, pp. 359--392, 1999.

    http://www.cs.umn.edu/~metis