Changeset 1884


Ignore:
Timestamp:
Apr 6, 2013 10:08:12 AM (5 years ago)
Author:
stefan
Message:

update changelog according to john's mail from 19th of March (cbc list)

http://list.coin-or.org/pipermail/cbc/2013-March/001061.html

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1 edited

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  • trunk/Cbc/README

    r1853 r1884  
    2626==========
    2727
    28 Release 2.8:
     28Release 2.8.0:
    2929
    30301. Introduced new secondaryStatus 8 to indicate that solving stopped due to an iteration limit.
     
    4444   probability of finding an improved solution by flipping a small number of binary variables), in particular
    4545   when it is applied to the first heuristic solutions found at the root node.
     46   
    46475. An implementation of Zero-Half-Cuts by Alberto Caprara is now available.
    4748   By default, these cuts are off.  To use add to your command line -zerohalfCuts root (or other options) or just -zero.
     
    4950
    5051   The implementation of these cuts is described in
    51    G. Andreello, A. Caprara, M. Fischetti
    52    â€œEmbedding Cuts in a Branch and Cut Framework: a Computational Study with {0,1/2}-Cuts”
     52   G. Andreello, A. Caprara, and M. Fischetti
     53   "Embedding Cuts in a Branch and Cut Framework: a Computational Study with {0,1/2}-Cuts"
    5354   INFORMS Journal on Computing 19(2), 229-238, 2007
    54 6.  Allow initialization of random seed by user.  Pseudo-random numbers are used in Cbc and Clp.  In Clp they
     55   http://dx.doi.org/10.1287/ijoc.1050.0162
     56
     576. An alternative implementation of a reduce and split cut generator by Giacomo Nannicini is now available.
     58   By default, these cuts are off.  To use add to your command line -reduce2AndSplitCuts root (or other options).
     59
     60   The implementation of these cuts is described in
     61   G. Cornuejols and G. Nannicini
     62   "Practical strategies for generating rank-1 split cuts in mixed-integer linear programming"
     63   Mathematical Programming Computation 3(4), 281-318, 2011
     64   http://dx.doi.org/10.1007/s12532-011-0028-6
     65
     667. An alternative robust implementation of a Gomory cut generator by Giacomo Nannicini is now available.
     67   By default, these cuts are off.  To use add to your command line -GMI root (or other options).
     68
     69   The implementation of these cuts is described in
     70   G. Cornuejols, F. Margot, and G. Nannicini
     71   "On the safety of Gomory cut generators"
     72   http://faculty.sutd.edu.sg/~nannicini/index.php?page=publications
     73   
     748.  Allow initialization of random seed by user.  Pseudo-random numbers are used in Cbc and Clp.  In Clp they
    5575   are used to break ties in degenerate problems, while in Cbc heuristics such as the Feasibility Pump use them   
    5676   to decide whether to round up or down.  So if a different pseudo-random seed is given to Clp then you may get
     
    5878   setting randomSeed for Clp and/or randomCbcSeed for Cbc.  The special value of 0 tells code to use time of day
    5979   for initial seed.
    60 7.  Building on this idea Andrea Lodi , Matteo Fischetti , Michele Monaci , Domenico Salvagnin and Andrea Tramontani
     80   
     819.  Building on this idea Andrea Lodi, Matteo Fischetti, Michele Monaci, Domenico Salvagnin and Andrea Tramontani
    6182   suggest that this idea be be improved by running at the root node with multiple copies of solver, each
    6283   with its own different seed and then passing in the solutions and cuts so that the main solver has a richer
    6384   set of solutions and possibly stronger cuts.  This is switched on by setting multipleRootPasses.  These can also
    6485   be done in parallel.
     86 
     8710. Few changes to presolve for special variables and badly scaled problems (in CoinUtils).
    6588
     8911. New option -extraVariables <number> which switches on a trivial re-formulation to group variables with same cost together.
    6690
    6791
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