My Constraint Programming Blog

Comet version 2.0 has been released! That's great news.

Version 2.0 can be downloaded from Dynadec's Download page.

Here are the improvements in version 2.0 compared to version 1.2.

This release has the following new features [with bug tracking id where applicable]:
Major additions:

    * The SCIP MIP solver is now included (See license agreement for details)
    * Java API wrapper around the C++ API using Java Native Interface
    * Global Constraints for Rostering (stretch and regular) and Soft Global Constraints 
      (atLeastNValue, softCardinality, softAtMost, softAtLeast)

Other improvements:

    * Directory browsing support [#286]
    * Equality testing between ranges [#285]
    * Added getCPSolver(expr{int}) [#294]
    * Removed debugging printouts from C++ interface [#305]
    * Added inputFloatArrayArray to the C++ interface [#261]
    * Added support for arrays of ranges [#269]
    * Added changes() event to var{float} [#214]
    * Added access (by copy) to the set of a trail{set} [#196]
    * Added events on var{float} [#208]
    * Added clear method on VisualTextTable (qtvisual) [#310]
    * Improved zooming in the VisualDrawingBoard (qtvisual)
    * Additions to the Tutorial:
          o introduction to the Comparable interface,
          o trigonometric functions,
          o a section with an example on user defined reified constraints,
          o list of methods available for incremental variables.

Included from the 2.0 Beta release
Major additions:

    * New XML library (cotxml).
    * New visualization library (qtvisual) using the Qt toolkit on all platforms
    * New graphical debugger (-gqt command line option) using the Qt 
      library on all platforms
    * New support for external plugins
    * New Comet language documentation with code samples

Other improvements:

    * JIT level 2 is now the default [#259]
    * New quiet mode with -q switch [#229]
    * Addition functionality in FloatExpr [#233]
    * Improved support for normalization and large domains [#236]
    * Added support for Solver::getSolution() with satisfaction problems. [#146]
    * Added a "Stop" button to the debugger to interrupt running programs. [#186]
    * Added support for an array of sets of strings [#194]
    * Added support for hexadecimal constants. [#217]
    * Added support for constraint handles from expressions [#203]
    * Added string comparison method [#235]
    * Improved scalability in linear expressions in CP [#251]
    * Added bounds checking on individual indices of matrices [#271]
    * Added events to CP float variables [#208]
    * Added multiknapsackWithPrecedences constraint in CP

Some comments

Comet tutorial
In Comet version 2.0-Beta released I was excited about the Comet tutorial. I have now read it (the Beta version). It is a great work that explains very well in detail (and with many examples) the three different modeling paradigms of Comet: constraint programming, constraint-based local search, and mathematical programming.

My Comet models
I have also changed some of my Comet models so they run with version 2.0:

• nonogram_regular.co : There is now a built in regular constraint, but I'm still using my own home-brewed which is renamed to myregular. (I have to test the model using the built-in constraint. Update: Which I know have done, see below.)
• Some of the models had the last element in a list followed by a , which is not supported any more.

Update: I have also added some models which use some of the new functionality in version 2.0:

• steiner_sets.co that use variable sets, i.e. var{set{int}}.
• least_diff_gui.co, my standard problem Least diff problem with animation of the solution (and the search tree) using the new qtvisual library.
• diet_gui.co: simple Diet problem with animation of the solution (and search tree) using the new qtvisual library.
• debruijn_gui.co, de Bruijn sequence. As debruijn.co with animation of the solution (and the search tree) using the new qtvisual library.
• nonogram_automaton.co: A version of nonogram_regular.co (which used my home-brewn version of regular constraint), using the new built-in regular constraint and Automaton.