[R-pkgs] New package: relations

[David Meyer]

Dear useRs,

it is our great pleasure to announce the new package "relations" to
appear on all CRAN-mirrors soon.

This package provides data structures and methods for creating and
manipulating relations, relation ensembles, sets, and tuples. The
feature list includes:

* creation of relations by domain and graph/characteristic
function/incidences,

* extraction of characteristic function and graph,

* predicate functions for the most common standard characteristics,

* operators known from relational algebra theory (such as projection,
selection, cartesian product, joins, etc.),

* transitive/reflexive reduction and closure of a relation,

* relation ensembles for combining relations,

* fitters for determining (possibly all) consensus relations of a
relation ensemble including the Borda and Condorcet methods, as well as
exact solvers for minimizing a criterion function based on the symmetric
difference (Kemeny-Snell) metric.

* a simple plot method for Hasse-diagrams using RGraphviz.


Kurt and David