source: stable/2.9/README.md @ 2160

Last change on this file since 2160 was 2160, checked in by tkr, 3 years ago

Merging r2159 from trunk

File size: 9.4 KB
Line 
1# CBC Version 2.9.3 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11(somehwat outdated) user's manual is available here: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 2.9.3
40
41   * Minor bug fixes
42
43 * Release 2.9.2
44
45   * Fix for proper installation with ```DESTDIR```
46
47 * Release 2.9.1
48
49   * Fix for dependency linking
50   * Minor bug fixes
51
52 * Release 2.9.0
53
54   * Introduced specialized branching methods for dealing with "big Ms".
55   * Introduced new methods for dealing with symmetry (requires installation of [nauty](http://pallini.di.uniroma1.it/))
56   * Introduction of conflict cuts (off by default, turn on with `-constraint conflict`)
57
58 * Release 2.8.13
59
60   * Improved message handling
61   * Miscellaneous bug fixes.
62
63 * Release 2.8.12
64
65   * Update for dependencies.
66
67 * Release 2.8.11
68
69   * Major overhaul of C interface
70   * Fixes to SOS
71   * Miscellaneous bug fixes
72
73 * Release 2.8.10
74
75   * More changes related to thread safety.
76   * Fix bug in build system with Visual Studio compiler.
77   * Miscellaneous bug fixes.
78
79 * Release 2.8.9
80
81   * Attempt to make Cbc thread safe.
82   * Add parallel examples.
83   * Add CbcSolverUsefulInfo.
84   * Bug fixes.
85
86 * Release 2.8.8
87
88   * Added example to show how to use Cbc with installed libraries in MSVC++
89   * Fixed inconsistency in addition of libCbcSolver to dependencies in
90     {{{cbc_addlibs.txt}}}.
91
92 * Release 2.8.7
93
94   * Changed so that Doxygen builds LaTex
95   * Fixes for build system
96
97 * Release 2.8.6
98
99   * Added option to explicitly link dependencies to comply with packaging
100     requirements on Fedora and Debian, as well as allow building of MinGW
101     DLLs.
102
103 * Release 2.8.5
104
105   * Minor fixes to build system
106
107 * Release 2.8.4
108
109   * Small bug fixes
110   * Upgrades to build system
111
112 * Release 2.8.3:
113
114   * Fix for handling SOS.
115
116 * Release 2.8.2:
117
118   * Fixed recognition of Glpk source in main configure.
119   * Minor bug fixes in CoinUtils, Clp, and Cbc.
120
121 * Release 2.8.1:
122
123   * Minor bug fixes
124
125 * Release 2.8.0:
126
127   * Introduced new secondaryStatus 8 to indicate that solving stopped due to
128     an iteration limit.
129   * Solution pool is now accessible via the command line and the CbcMain*
130     interface.
131   * New mipstart option to read an initial feasible solution from a file.
132     Only values for discrete variables need to be provided.
133
134   * Added Proximity Search heuristic by Fischetti and Monaci (off by
135     default): The simplest way to switch it on using stand-alone version is
136     ```-proximity on```.
137
138     Proximity Search is the new "No-Neighborhood Search" 0-1 MIP refinement
139     heuristic recently proposed by Fischetti and Monaci (2012). The idea is
140     to define a sub-MIP without additional constraints but with a modified
141     objective function intended to attract the search in the proximity of the
142     incumbent. The approach works well for 0-1 MIPs whose solution landscape
143     is not too irregular (meaning the there is reasonable probability of
144     finding an improved solution by flipping a small number of binary
145     variables), in particular when it is applied to the first heuristic
146     solutions found at the root node.
147   
148   * An implementation of Zero-Half-Cuts by Alberto Caprara is now available.
149     By default, these cuts are off. To use add to your command line
150     -zerohalfCuts root (or other options) or just -zero. So far, they may
151     help only on a small subset of problems and may need some tuning.
152
153     The implementation of these cuts is described in G. Andreello, A.
154     Caprara, and M. Fischetti "Embedding Cuts in a Branch and Cut Framework:
155     a Computational Study with {0,1/2}-Cuts" INFORMS Journal on Computing
156     19(2), 229-238, 2007 http://dx.doi.org/10.1287/ijoc.1050.0162
157
158   * An alternative implementation of a reduce and split cut generator by
159     Giacomo Nannicini is now available. By default, these cuts are off. To
160     use add to your command line -reduce2AndSplitCuts root (or other
161     options).
162
163     The implementation of these cuts is described in G. Cornuejols and G.
164     Nannicini "Practical strategies for generating rank-1 split cuts in
165     mixed-integer linear programming" Mathematical Programming Computation
166     3(4), 281-318, 2011 http://dx.doi.org/10.1007/s12532-011-0028-6
167
168   * An alternative robust implementation of a Gomory cut generator by Giacomo
169     Nannicini is now available. By default, these cuts are off. To use add to
170     your command line -GMI root (or other options).
171
172     The implementation of these cuts is described in G. Cornuejols, F.
173     Margot, and G. Nannicini "On the safety of Gomory cut generators"
174     http://faculty.sutd.edu.sg/~nannicini/index.php?page=publications
175
176   * To encourage the use of some of the more exotic/expensive cut generators
177     a parameter -slowcutpasses has been added. The idea is that the code does
178     these cuts just a few times - less than the more usual cuts. The default
179     is 10. The cut generators identified by "may be slow" at present are just
180     Lift and project and ReduceAndSplit (both versions).
181   
182   * Allow initialization of random seed by user. Pseudo-random numbers are
183     used in Cbc and Clp. In Clp they are used to break ties in degenerate
184     problems, while in Cbc heuristics such as the Feasibility Pump use them
185     to decide whether to round up or down. So if a different pseudo-random
186     seed is given to Clp then you may get a different continuous optimum and
187     so different cuts and heuristic solutions. This can be switched on by
188     setting randomSeed for Clp and/or randomCbcSeed for Cbc. The special
189     value of 0 tells code to use time of day for initial seed.
190   
191   * Building on this idea, Andrea Lodi, Matteo Fischetti, Michele Monaci,
192     Domenico Salvagnin, Yuji Shinano, and Andrea Tramontani suggest that this
193     idea be improved by running at the root node with multiple copies of
194     solver, each with its own different seed and then passing in the
195     solutions and cuts so that the main solver has a richer set of solutions
196     and possibly stronger cuts. This is switched on by setting
197     -multipleRootPasses. These can also be done in parallel.
198 
199   * Few changes to presolve for special variables and badly scaled problems
200     (in CoinUtils).
201
202   * New option -extraVariables <number> which switches on a trivial
203    re-formulation that introduces extra integer variables to group together
204    variables with same cost.
205
206   * For some problems, cut generators and general branching work better if
207     the problem would be infeasible if the cost is too high. If the new
208     option -constraintFromCutoff is set, the objective function is added as a
209     constraint which rhs is set to the current cutoff value (objective value
210     of best known solution).
211
212 * Release 2.7.8:
213
214   * Change message when LP simplex iteration limit is hit from "Exiting on
215     maximum nodes" to "Exiting on maximum number of iterations"
216   * Fix for using overlapping SOS.
217   * Fixes in buildsystem.
218
219 * Release 2.7.7:
220
221   * Fix to report interruption on user event if SIGINT is received by
222     CbcSolver. model->status() should now be 5 if this event happened. Added
223     method CbcModel::sayEventHappened() to make cbc stop due to an 'user
224     event'.
225
226   * Other minor fixes.
227
228 * Release 2.7.6:
229
230   * Fixes to build system.
231
232   * Other minor fixes.
233
234 * Release 2.7.5:
235
236   * Fixes to get AMPL interface working again.
237
238   * More fixes to MSVC++ files.
239
240 * Release 2.7.4:
241
242   * Minor bugfixes.
243
244 * Release 2.7.3:
245
246   * Minor bugfixes.
247
248   * Fixes to MSVC++ files.
249
250 * Release 2.7.2:
251
252   * Allow row/column names for GMPL models.
253
254   * Added CbcModel::haveMultiThreadSupport() to indicate whether Cbc library
255     has been compiled with multithread support.
256
257   * Added CbcModel::waitingForMiniBranchAndBound() to indicate whether
258     sub-MIP heuristic is currently running.
259
260   * Cbc shell should work with readline if configured with
261     ```--enable-gnu-packages```.
262
263   * Support for compressed input files (.gz, .bz2) is now enabled by default.
264
265   * Fix problems with relative gap tolerance > 100% and further bugs.
266
267   * Fixes for MSVC++ Version 9 files.
268
269   * Minor fixes in buildsystem; update to BuildTools 0.7.1.
270
271 * Release 2.7.1:
272
273   * Fixes to MSVC++ files
274
275 * Release 2.7.0:
276
277   * License has been changed to the EPL.
278
279   * Support for MSVC++ version 10 added.
280
281   * Support for BuildTools version 0.7 to incorporate recent enhancements,
282     including proper library versioning in Linux, prohibiting installation of
283     private headers, etc.
284
285   * Updated externals to new stable versions of dependent projects.
286
287   * Improvements to heuristics.
288
289   * New options for cut generation.
290
291   * Improved reporting of results.
292
293   * Improvements to documentation.
294
295   * Minor bug fixes.
296
297
Note: See TracBrowser for help on using the repository browser.