Fri, 17 Apr 2009 18:04:36 +0200Support >= and <= constraints in NetworkSimplex (#219, #234)
Peter Kovacs <kpeter@inf.elte.hu> [Fri, 17 Apr 2009 18:04:36 +0200] rev 609
Support >= and <= constraints in NetworkSimplex (#219, #234)

By default the same inequality constraints are supported as by
Circulation (the GEQ form), but the LEQ form can also be selected
using the problemType() function.

The documentation of the min. cost flow module is reworked and
extended with important notes and explanations about the different
variants of the problem and about the dual solution and optimality
conditions.

Fri, 03 Apr 2009 18:59:15 +0200Support real types + numerical stability fix in NS (#254)
Peter Kovacs <kpeter@inf.elte.hu> [Fri, 03 Apr 2009 18:59:15 +0200] rev 608
Support real types + numerical stability fix in NS (#254)

- Real types are supported by appropriate inicialization.
- A feature of the XTI spanning tree structure is removed to ensure
numerical stability (could cause problems using integer types).
The node potentials are updated always on the lower subtree,
in order to prevent overflow problems.
The former method isn't notably faster during to our tests.

Fri, 03 Apr 2009 13:46:16 +0200Separate types for flow and cost values in NetworkSimplex (#234)
Peter Kovacs <kpeter@inf.elte.hu> [Fri, 03 Apr 2009 13:46:16 +0200] rev 607
Separate types for flow and cost values in NetworkSimplex (#234)

Wed, 25 Mar 2009 21:37:50 +0100Support multiple run() calls in NetworkSimplex (#234)
Peter Kovacs <kpeter@inf.elte.hu> [Wed, 25 Mar 2009 21:37:50 +0100] rev 606
Support multiple run() calls in NetworkSimplex (#234)

Wed, 25 Mar 2009 15:58:44 +0100Rework the interface of NetworkSimplex (#234)
Peter Kovacs <kpeter@inf.elte.hu> [Wed, 25 Mar 2009 15:58:44 +0100] rev 605
Rework the interface of NetworkSimplex (#234)

The parameters of the problem can be set with separate functions
instead of different constructors.

Tue, 24 Mar 2009 00:18:25 +0100Use XTI implementation instead of ATI in NetworkSimplex (#234)
Peter Kovacs <kpeter@inf.elte.hu> [Tue, 24 Mar 2009 00:18:25 +0100] rev 604
Use XTI implementation instead of ATI in NetworkSimplex (#234)

XTI (eXtended Threaded Index) is an imporved version of the widely
known ATI (Augmented Threaded Index) method for storing and updating
the spanning tree structure in Network Simplex algorithms.

In the ATI data structure three indices are stored for each node:
predecessor, thread and depth. In the XTI data structure depth is
replaced by the number of successors and the last successor
(according to the thread index).

Mon, 23 Mar 2009 23:54:42 +0100Internal restructuring and renamings in NetworkSimplex (#234)
Peter Kovacs <kpeter@inf.elte.hu> [Mon, 23 Mar 2009 23:54:42 +0100] rev 603
Internal restructuring and renamings in NetworkSimplex (#234)