source: stable/2.9/Cbc/README @ 2219

Last change on this file since 2219 was 2219, checked in by tkr, 4 years ago

Merging r2218 from trunk

  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
File size: 9.5 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11(somehwat outdated) user's manual is available here: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 2.9.6
40
41   * Small bug fixes
42
43 * Release 2.9.5
44
45   * Small bug fixes
46
47 * Release 2.9.4
48
49   * Small fixes for stability
50   * Fixes for Doygen documentation generation
51
52 * Release 2.9.3
53
54   * Minor bug fixes
55
56 * Release 2.9.2
57
58   * Fix for proper installation with ```DESTDIR```
59
60 * Release 2.9.1
61
62   * Fix for dependency linking
63   * Minor bug fixes
64
65 * Release 2.9.0
66
67   * Introduced specialized branching methods for dealing with "big Ms".
68   * Introduced new methods for dealing with symmetry (requires installation of [nauty](http://pallini.di.uniroma1.it/))
69   * Introduction of conflict cuts (off by default, turn on with `-constraint conflict`)
70
71 * Release 2.8.13
72
73   * Improved message handling
74   * Miscellaneous bug fixes.
75
76 * Release 2.8.12
77   * Update for dependencies.
78
79 * Release 5.8.11
80
81   * Major overhaul of C interface
82   * Fixes to SOS
83   * Miscellaneous bug fixes
84
85 * Release 2.8.10
86
87   * More changes related to thread safety.
88   * Fix bug in build system with Visual Studio compiler.
89   * Miscellaneous bug fixes.
90
91 * Release 2.8.9
92
93   * Attempt to make Cbc thread safe.
94   * Add parallel examples.
95   * Add CbcSolverUsefulInfo.
96   * Bug fixes.
97
98 * Release 2.8.8
99
100   * Added example to show how to use Cbc with installed libraries in MSVC++
101   * Fixed inconsistency in addition of libCbcSolver to dependencies in
102     {{{cbc_addlibs.txt}}}.
103
104 * Release 2.8.7
105
106   * Changed so that Doxygen builds LaTex
107   * Fixes for build system
108
109 * Release 2.8.6
110
111   * Added option to explicitly link dependencies to comply with packaging
112     requirements on Fedora and Debian, as well as allow building of MinGW
113     DLLs.
114
115 * Release 2.8.5
116
117   * Minor fixes to build system
118
119 * Release 2.8.4
120   * Small bug fixes
121   * Upgrades to build system
122
123 * Release 2.8.3:
124
125   * Fix for handling SOS.
126
127 * Release 2.8.2:
128
129   * Fixed recognition of Glpk source in main configure.
130   * Minor bug fixes in CoinUtils, Clp, and Cbc.
131
132 * Release 2.8.1:
133
134   * Minor bug fixes
135
136 * Release 2.8.0:
137
138   * Introduced new secondaryStatus 8 to indicate that solving stopped due to
139     an iteration limit.
140   * Solution pool is now accessible via the command line and the CbcMain*
141     interface.
142   * New mipstart option to read an initial feasible solution from a file.
143     Only values for discrete variables need to be provided.
144
145   * Added Proximity Search heuristic by Fischetti and Monaci (off by
146     default): The simplest way to switch it on using stand-alone version is
147     ```-proximity on```.
148
149     Proximity Search is the new "No-Neighborhood Search" 0-1 MIP refinement
150     heuristic recently proposed by Fischetti and Monaci (2012). The idea is
151     to define a sub-MIP without additional constraints but with a modified
152     objective function intended to attract the search in the proximity of the
153     incumbent. The approach works well for 0-1 MIPs whose solution landscape
154     is not too irregular (meaning the there is reasonable probability of
155     finding an improved solution by flipping a small number of binary
156     variables), in particular when it is applied to the first heuristic
157     solutions found at the root node.
158   
159   * An implementation of Zero-Half-Cuts by Alberto Caprara is now available.
160     By default, these cuts are off. To use add to your command line
161     -zerohalfCuts root (or other options) or just -zero. So far, they may
162     help only on a small subset of problems and may need some tuning.
163
164     The implementation of these cuts is described in G. Andreello, A.
165     Caprara, and M. Fischetti "Embedding Cuts in a Branch and Cut Framework:
166     a Computational Study with {0,1/2}-Cuts" INFORMS Journal on Computing
167     19(2), 229-238, 2007 http://dx.doi.org/10.1287/ijoc.1050.0162
168
169   * An alternative implementation of a reduce and split cut generator by
170     Giacomo Nannicini is now available. By default, these cuts are off. To
171     use add to your command line -reduce2AndSplitCuts root (or other
172     options).
173
174     The implementation of these cuts is described in G. Cornuejols and G.
175     Nannicini "Practical strategies for generating rank-1 split cuts in
176     mixed-integer linear programming" Mathematical Programming Computation
177     3(4), 281-318, 2011 http://dx.doi.org/10.1007/s12532-011-0028-6
178
179   * An alternative robust implementation of a Gomory cut generator by Giacomo
180     Nannicini is now available. By default, these cuts are off. To use add to
181     your command line -GMI root (or other options).
182
183     The implementation of these cuts is described in G. Cornuejols, F.
184     Margot, and G. Nannicini "On the safety of Gomory cut generators"
185     http://faculty.sutd.edu.sg/~nannicini/index.php?page=publications
186
187   * To encourage the use of some of the more exotic/expensive cut generators
188     a parameter -slowcutpasses has been added. The idea is that the code does
189     these cuts just a few times - less than the more usual cuts. The default
190     is 10. The cut generators identified by "may be slow" at present are just
191     Lift and project and ReduceAndSplit (both versions).
192   
193   * Allow initialization of random seed by user. Pseudo-random numbers are
194     used in Cbc and Clp. In Clp they are used to break ties in degenerate
195     problems, while in Cbc heuristics such as the Feasibility Pump use them
196     to decide whether to round up or down. So if a different pseudo-random
197     seed is given to Clp then you may get a different continuous optimum and
198     so different cuts and heuristic solutions. This can be switched on by
199     setting randomSeed for Clp and/or randomCbcSeed for Cbc. The special
200     value of 0 tells code to use time of day for initial seed.
201   
202   * Building on this idea, Andrea Lodi, Matteo Fischetti, Michele Monaci,
203     Domenico Salvagnin, Yuji Shinano, and Andrea Tramontani suggest that this
204     idea be improved by running at the root node with multiple copies of
205     solver, each with its own different seed and then passing in the
206     solutions and cuts so that the main solver has a richer set of solutions
207     and possibly stronger cuts. This is switched on by setting
208     -multipleRootPasses. These can also be done in parallel.
209 
210   * Few changes to presolve for special variables and badly scaled problems
211     (in CoinUtils).
212
213   * New option -extraVariables <number> which switches on a trivial
214    re-formulation that introduces extra integer variables to group together
215    variables with same cost.
216
217   * For some problems, cut generators and general branching work better if
218     the problem would be infeasible if the cost is too high. If the new
219     option -constraintFromCutoff is set, the objective function is added as a
220     constraint which rhs is set to the current cutoff value (objective value
221     of best known solution).
222
223 * Release 2.7.8:
224
225   * Change message when LP simplex iteration limit is hit from "Exiting on
226     maximum nodes" to "Exiting on maximum number of iterations"
227   * Fix for using overlapping SOS.
228   * Fixes in buildsystem.
229
230 * Release 2.7.7:
231
232   * Fix to report interruption on user event if SIGINT is received by
233     CbcSolver. model->status() should now be 5 if this event happened. Added
234     method CbcModel::sayEventHappened() to make cbc stop due to an 'user
235     event'.
236
237   * Other minor fixes.
238
239 * Release 2.7.6:
240
241   * Fixes to build system.
242
243   * Other minor fixes.
244
245 * Release 2.7.5:
246
247   * Fixes to get AMPL interface working again.
248
249   * More fixes to MSVC++ files.
250
251 * Release 2.7.4:
252
253   * Minor bugfixes.
254
255 * Release 2.7.3:
256
257   * Minor bugfixes.
258
259   * Fixes to MSVC++ files.
260
261 * Release 2.7.2:
262
263   * Allow row/column names for GMPL models.
264
265   * Added CbcModel::haveMultiThreadSupport() to indicate whether Cbc library
266     has been compiled with multithread support.
267
268   * Added CbcModel::waitingForMiniBranchAndBound() to indicate whether
269     sub-MIP heuristic is currently running.
270
271   * Cbc shell should work with readline if configured with
272     ```--enable-gnu-packages```.
273
274   * Support for compressed input files (.gz, .bz2) is now enabled by default.
275
276   * Fix problems with relative gap tolerance > 100% and further bugs.
277
278   * Fixes for MSVC++ Version 9 files.
279
280   * Minor fixes in buildsystem; update to BuildTools 0.7.1.
281
282 * Release 2.7.1:
283
284   * Fixes to MSVC++ files
285
286 * Release 2.7.0:
287
288   * License has been changed to the EPL.
289
290   * Support for MSVC++ version 10 added.
291
292   * Support for BuildTools version 0.7 to incorporate recent enhancements,
293     including proper library versioning in Linux, prohibiting installation of
294     private headers, etc.
295
296   * Updated externals to new stable versions of dependent projects.
297
298   * Improvements to heuristics.
299
300   * New options for cut generation.
301
302   * Improved reporting of results.
303
304   * Improvements to documentation.
305
306   * Minor bug fixes.
307
308
Note: See TracBrowser for help on using the repository browser.