[Coin-discuss] Cbc branchAndBound

[John J Forrest]

only in branches/devel


                                                                           
             "Matthew Galati"                                              
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             03/16/07 12:27 PM         RE: [Coin-discuss] Cbc              
                                       branchAndBound                      
                                                                           
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Ok - so CbcStrategyDefault is not really the default strategy for Cbc.
don't see:
 or
From: coin-discuss-bounces at list.coin-or.org
[mailto:coin-discuss-bounces at list.coin-or.org] On Behalf Of John J
Forrest
source software for Operations Research
branchAndBound
time to do much for a week or so, but there are options to the
CbcStrategyDefault constructor - so try setting preprocessing and cuts in
tree and see what you think - see examples/strategy.cpp.  Also there are
more heuristics - see examples/strategy2.cpp
either example.



             "Matthew Galati"
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                                                                   Subject
             03/15/07 09:53 AM         RE: [Coin-discuss] Cbc
                                       branchAndBound

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Hi -- lots of related discussion on other threads. Solutions all seem to
involve a re-design or new version of OSI.
simple question?
  CbcModel cbc(*si);
  CbcStrategyDefault cbcStrategyDefault;
  cbc.setStrategy(cbcStrategyDefault);
  cbc.branchAndBound();
CoinSolve.cpp? From experimentation, just running cbc.branchAndBound()
without setting the strategy is a bad idea.
need to use CbcModel::branchAndBound(), OsiCbc::branchAndBound(),
FunkyChickenDance::solveMyMip() -- I just want to solve a (generic) MILP
(with the best known default settings) that is currently stored in an OSI
object. How do I do that?

Thanks.
[mailto:coin-discuss-bounces at list.coin-or.org] On Behalf Of Matthew Galati
source software for Operations Research branchAndBound seem to be on:
  CbcModel cbc(*si);
  CbcStrategyDefault cbcStrategyDefault;
  cbc.setStrategy(cbcStrategyDefault);
  cbc.branchAndBound();
( ), and there seems to be a lot going on there - and it is hard to follow.
I would suspect that libCbc should have the same functionality and
performance as the cbc executable. Maybe some of CoinSolve needs to be
moved back into the library? So that the solve part of main() just calls
cbc.solve(), or something like this.
coin-discuss-bounces at list.coin-or.org
[mailto:coin-discuss-bounces at list.coin-or.org] On Behalf Of Matthew Galati
source software for Operations Research branchAndBound
   CbcModel cbc(*si);
   cbc.branchAndBound( );
the CBC exe from CoinSolve.cpp. Apparently, by default branchAndBound() has
all cuts, etc turned off. What's the best interface from CbcModel to solve
a MIP so that it performs like the CBC exe?

Thanks,
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