May 2004: avoid edge weight manipulations in R?

Plan of Oct 2003
----------------
1) rationalize graph and BGL approaches to undirected
graphs -- graph wants reciprocated directed edges, BGL
does not
2) implement interfaces for
  a) connected components
  b) maximum flow/minimum disconnecting set

Plan of July 2003
1) state basic constraints:
  a) all edge weights will be coerced to double on way in
  b) separate C++ functions need to be written for directed
     and undirected inputs
2) simplify the C++ source of the R interfaces

Plan of April 2003

1) Use Boost 1.30.0 and make sure library
still works for tsort and DAG cycle check
*DONE 2 April

2) convert tsort application to .Call interface

3) get a better grip on how R data can be converted
to Boost graphs, and bring in a graph with weights
or distances

4) deploy their MST method and compare to R mstree
*KMST is in 2 april

5) list the applications we want to have and try
to get a generic interface

6) consider building boost graphs in R by
manipulating pointer structures.  perhaps this
should be the highest priority!  boostGraph
as a descendant of graph