Changeset 1888 for stable/2.8/Cbc/README

Timestamp:

Apr 6, 2013 4:52:59 PM (8 years ago)

Author:

stefan

Message:

sync with trunk rev 1887

Location:

stable/2.8/Cbc

Files:

• . (modified) (1 prop)
• README (modified) (4 diffs)

stable/2.8/Cbc/README

@@ -26 +26 @@
 ==========
 
-Release 2.8:
+Release 2.8.0:
 
 1. Introduced new secondaryStatus 8 to indicate that solving stopped due to an iteration limit.
@@ -44 +44 @@
    probability of finding an improved solution by flipping a small number of binary variables), in particular 
    when it is applied to the first heuristic solutions found at the root node.
+   
 5. An implementation of Zero-Half-Cuts by Alberto Caprara is now available.
    By default, these cuts are off.  To use add to your command line -zerohalfCuts root (or other options) or just -zero.
@@ -49 +50 @@
 
    The implementation of these cuts is described in
-   G. Andreello, A. Caprara, M. Fischetti
-   “Embedding Cuts in a Branch and Cut Framework: a Computational Study with {0,1/2}-Cuts”
+   G. Andreello, A. Caprara, and M. Fischetti
+   "Embedding Cuts in a Branch and Cut Framework: a Computational Study with {0,1/2}-Cuts"
    INFORMS Journal on Computing 19(2), 229-238, 2007
-6.  Allow initialization of random seed by user.  Pseudo-random numbers are used in Cbc and Clp.  In Clp they
+   http://dx.doi.org/10.1287/ijoc.1050.0162
+
+6. An alternative implementation of a reduce and split cut generator by Giacomo Nannicini is now available.
+   By default, these cuts are off.  To use add to your command line -reduce2AndSplitCuts root (or other options).
+
+   The implementation of these cuts is described in
+   G. Cornuejols and G. Nannicini
+   "Practical strategies for generating rank-1 split cuts in mixed-integer linear programming"
+   Mathematical Programming Computation 3(4), 281-318, 2011
+   http://dx.doi.org/10.1007/s12532-011-0028-6
+
+7. An alternative robust implementation of a Gomory cut generator by Giacomo Nannicini is now available.
+   By default, these cuts are off.  To use add to your command line -GMI root (or other options).
+
+   The implementation of these cuts is described in
+   G. Cornuejols, F. Margot, and G. Nannicini
+   "On the safety of Gomory cut generators"
+   http://faculty.sutd.edu.sg/~nannicini/index.php?page=publications
+   
+8.  Allow initialization of random seed by user.  Pseudo-random numbers are used in Cbc and Clp.  In Clp they
    are used to break ties in degenerate problems, while in Cbc heuristics such as the Feasibility Pump use them   
    to decide whether to round up or down.  So if a different pseudo-random seed is given to Clp then you may get
@@ -58 +78 @@
    setting randomSeed for Clp and/or randomCbcSeed for Cbc.  The special value of 0 tells code to use time of day
    for initial seed.
-7.  Building on this idea Andrea Lodi , Matteo Fischetti , Michele Monaci , Domenico Salvagnin and Andrea Tramontani
+   
+9.  Building on this idea Andrea Lodi, Matteo Fischetti, Michele Monaci, Domenico Salvagnin and Andrea Tramontani
    suggest that this idea be be improved by running at the root node with multiple copies of solver, each
    with its own different seed and then passing in the solutions and cuts so that the main solver has a richer
    set of solutions and possibly stronger cuts.  This is switched on by setting multipleRootPasses.  These can also
    be done in parallel.
+ 
+10. Few changes to presolve for special variables and badly scaled problems (in CoinUtils).
 
+11. New option -extraVariables <number> which switches on a trivial re-formulation to group variables with same cost together.