source: stable/2.9/Cbc/README @ 2223

Last change on this file since 2223 was 2223, checked in by tkr, 2 years ago

Merging r2221 and r2222 from trunk

  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
File size: 9.6 KB
Line 
1# CBC Version 2.9.4 README
2
3Welcome to the README for the COIN Branch and Cut Solver (CBC). CBC is
4distributed under the Eclipse Public License and is freely redistributable.
5All source code and documentation is Copyright IBM and others. This README may
6be redistributed freely.
7
8## DOCUMENTATION
9
10For a quick start guide, please see the INSTALL file in this distribution. A
11(somehwat outdated) user's manual is available here:
12
13http://www.coin-or.org/Cbc
14
15More up-to-date automatically generated documentation of the source code can
16be found here:
17
18http://www.coin-or.org/Doxygen/Cbc/
19
20Further information can be found here:
21
22http://projects.coin-or.org/Cbc
23
24## SUPPORT
25
26### List Serve
27
28CBC users should use the Cbc mailing list. To subscribe, go to
29http://list.coin-or.org/mailman/listinfo/cbc
30
31### Bug Reports
32
33Bug reports should be reported on the CBC development web site at
34
35https://projects.coin-or.org/Cbc/newticket
36
37## CHANGELOG
38
39 * Release 2.9.7
40
41   * Small bug fixes
42   * Option to switch to line buffered output
43
44 * Release 2.9.6
45
46   * Small bug fixes
47
48 * Release 2.9.5
49
50   * Small bug fixes
51
52 * Release 2.9.4
53
54   * Small fixes for stability
55   * Fixes for Doygen documentation generation
56
57 * Release 2.9.3
58
59   * Minor bug fixes
60
61 * Release 2.9.2
62
63   * Fix for proper installation with ```DESTDIR```
64
65 * Release 2.9.1
66
67   * Fix for dependency linking
68   * Minor bug fixes
69
70 * Release 2.9.0
71
72   * Introduced specialized branching methods for dealing with "big Ms".
73   * Introduced new methods for dealing with symmetry (requires installation of [nauty](http://pallini.di.uniroma1.it/))
74   * Introduction of conflict cuts (off by default, turn on with `-constraint conflict`)
75
76 * Release 2.8.13
77
78   * Improved message handling
79   * Miscellaneous bug fixes.
80
81 * Release 2.8.12
82   * Update for dependencies.
83
84 * Release 5.8.11
85
86   * Major overhaul of C interface
87   * Fixes to SOS
88   * Miscellaneous bug fixes
89
90 * Release 2.8.10
91
92   * More changes related to thread safety.
93   * Fix bug in build system with Visual Studio compiler.
94   * Miscellaneous bug fixes.
95
96 * Release 2.8.9
97
98   * Attempt to make Cbc thread safe.
99   * Add parallel examples.
100   * Add CbcSolverUsefulInfo.
101   * Bug fixes.
102
103 * Release 2.8.8
104
105   * Added example to show how to use Cbc with installed libraries in MSVC++
106   * Fixed inconsistency in addition of libCbcSolver to dependencies in
107     {{{cbc_addlibs.txt}}}.
108
109 * Release 2.8.7
110
111   * Changed so that Doxygen builds LaTex
112   * Fixes for build system
113
114 * Release 2.8.6
115
116   * Added option to explicitly link dependencies to comply with packaging
117     requirements on Fedora and Debian, as well as allow building of MinGW
118     DLLs.
119
120 * Release 2.8.5
121
122   * Minor fixes to build system
123
124 * Release 2.8.4
125   * Small bug fixes
126   * Upgrades to build system
127
128 * Release 2.8.3:
129
130   * Fix for handling SOS.
131
132 * Release 2.8.2:
133
134   * Fixed recognition of Glpk source in main configure.
135   * Minor bug fixes in CoinUtils, Clp, and Cbc.
136
137 * Release 2.8.1:
138
139   * Minor bug fixes
140
141 * Release 2.8.0:
142
143   * Introduced new secondaryStatus 8 to indicate that solving stopped due to
144     an iteration limit.
145   * Solution pool is now accessible via the command line and the CbcMain*
146     interface.
147   * New mipstart option to read an initial feasible solution from a file.
148     Only values for discrete variables need to be provided.
149
150   * Added Proximity Search heuristic by Fischetti and Monaci (off by
151     default): The simplest way to switch it on using stand-alone version is
152     ```-proximity on```.
153
154     Proximity Search is the new "No-Neighborhood Search" 0-1 MIP refinement
155     heuristic recently proposed by Fischetti and Monaci (2012). The idea is
156     to define a sub-MIP without additional constraints but with a modified
157     objective function intended to attract the search in the proximity of the
158     incumbent. The approach works well for 0-1 MIPs whose solution landscape
159     is not too irregular (meaning the there is reasonable probability of
160     finding an improved solution by flipping a small number of binary
161     variables), in particular when it is applied to the first heuristic
162     solutions found at the root node.
163   
164   * An implementation of Zero-Half-Cuts by Alberto Caprara is now available.
165     By default, these cuts are off. To use add to your command line
166     -zerohalfCuts root (or other options) or just -zero. So far, they may
167     help only on a small subset of problems and may need some tuning.
168
169     The implementation of these cuts is described in G. Andreello, A.
170     Caprara, and M. Fischetti "Embedding Cuts in a Branch and Cut Framework:
171     a Computational Study with {0,1/2}-Cuts" INFORMS Journal on Computing
172     19(2), 229-238, 2007 http://dx.doi.org/10.1287/ijoc.1050.0162
173
174   * An alternative implementation of a reduce and split cut generator by
175     Giacomo Nannicini is now available. By default, these cuts are off. To
176     use add to your command line -reduce2AndSplitCuts root (or other
177     options).
178
179     The implementation of these cuts is described in G. Cornuejols and G.
180     Nannicini "Practical strategies for generating rank-1 split cuts in
181     mixed-integer linear programming" Mathematical Programming Computation
182     3(4), 281-318, 2011 http://dx.doi.org/10.1007/s12532-011-0028-6
183
184   * An alternative robust implementation of a Gomory cut generator by Giacomo
185     Nannicini is now available. By default, these cuts are off. To use add to
186     your command line -GMI root (or other options).
187
188     The implementation of these cuts is described in G. Cornuejols, F.
189     Margot, and G. Nannicini "On the safety of Gomory cut generators"
190     http://faculty.sutd.edu.sg/~nannicini/index.php?page=publications
191
192   * To encourage the use of some of the more exotic/expensive cut generators
193     a parameter -slowcutpasses has been added. The idea is that the code does
194     these cuts just a few times - less than the more usual cuts. The default
195     is 10. The cut generators identified by "may be slow" at present are just
196     Lift and project and ReduceAndSplit (both versions).
197   
198   * Allow initialization of random seed by user. Pseudo-random numbers are
199     used in Cbc and Clp. In Clp they are used to break ties in degenerate
200     problems, while in Cbc heuristics such as the Feasibility Pump use them
201     to decide whether to round up or down. So if a different pseudo-random
202     seed is given to Clp then you may get a different continuous optimum and
203     so different cuts and heuristic solutions. This can be switched on by
204     setting randomSeed for Clp and/or randomCbcSeed for Cbc. The special
205     value of 0 tells code to use time of day for initial seed.
206   
207   * Building on this idea, Andrea Lodi, Matteo Fischetti, Michele Monaci,
208     Domenico Salvagnin, Yuji Shinano, and Andrea Tramontani suggest that this
209     idea be improved by running at the root node with multiple copies of
210     solver, each with its own different seed and then passing in the
211     solutions and cuts so that the main solver has a richer set of solutions
212     and possibly stronger cuts. This is switched on by setting
213     -multipleRootPasses. These can also be done in parallel.
214 
215   * Few changes to presolve for special variables and badly scaled problems
216     (in CoinUtils).
217
218   * New option -extraVariables <number> which switches on a trivial
219    re-formulation that introduces extra integer variables to group together
220    variables with same cost.
221
222   * For some problems, cut generators and general branching work better if
223     the problem would be infeasible if the cost is too high. If the new
224     option -constraintFromCutoff is set, the objective function is added as a
225     constraint which rhs is set to the current cutoff value (objective value
226     of best known solution).
227
228 * Release 2.7.8:
229
230   * Change message when LP simplex iteration limit is hit from "Exiting on
231     maximum nodes" to "Exiting on maximum number of iterations"
232   * Fix for using overlapping SOS.
233   * Fixes in buildsystem.
234
235 * Release 2.7.7:
236
237   * Fix to report interruption on user event if SIGINT is received by
238     CbcSolver. model->status() should now be 5 if this event happened. Added
239     method CbcModel::sayEventHappened() to make cbc stop due to an 'user
240     event'.
241
242   * Other minor fixes.
243
244 * Release 2.7.6:
245
246   * Fixes to build system.
247
248   * Other minor fixes.
249
250 * Release 2.7.5:
251
252   * Fixes to get AMPL interface working again.
253
254   * More fixes to MSVC++ files.
255
256 * Release 2.7.4:
257
258   * Minor bugfixes.
259
260 * Release 2.7.3:
261
262   * Minor bugfixes.
263
264   * Fixes to MSVC++ files.
265
266 * Release 2.7.2:
267
268   * Allow row/column names for GMPL models.
269
270   * Added CbcModel::haveMultiThreadSupport() to indicate whether Cbc library
271     has been compiled with multithread support.
272
273   * Added CbcModel::waitingForMiniBranchAndBound() to indicate whether
274     sub-MIP heuristic is currently running.
275
276   * Cbc shell should work with readline if configured with
277     ```--enable-gnu-packages```.
278
279   * Support for compressed input files (.gz, .bz2) is now enabled by default.
280
281   * Fix problems with relative gap tolerance > 100% and further bugs.
282
283   * Fixes for MSVC++ Version 9 files.
284
285   * Minor fixes in buildsystem; update to BuildTools 0.7.1.
286
287 * Release 2.7.1:
288
289   * Fixes to MSVC++ files
290
291 * Release 2.7.0:
292
293   * License has been changed to the EPL.
294
295   * Support for MSVC++ version 10 added.
296
297   * Support for BuildTools version 0.7 to incorporate recent enhancements,
298     including proper library versioning in Linux, prohibiting installation of
299     private headers, etc.
300
301   * Updated externals to new stable versions of dependent projects.
302
303   * Improvements to heuristics.
304
305   * New options for cut generation.
306
307   * Improved reporting of results.
308
309   * Improvements to documentation.
310
311   * Minor bug fixes.
312
313
Note: See TracBrowser for help on using the repository browser.