[Coin-symphony] Error in a header file and Help in embedding a "lp_solver" package.

[Ted Ralphs]

The header file you refer to is part of the COIN build tools project,
not part of SYMPHONY. The change you made will probably work fine on
most architectures, but just because it compiled does mean the generated
code will be correct. At any rate, to report this incompatibility,
please file a trouble ticket with the COIN BuildTools project:

https://projects.coin-or.org/BuildTools/newticket

A safer route, however, is to upgrade to MSVC++ Version 8. The Visual
Studio Express Edition is free and will compile SYMPHONY 5.1.1 without
any problems.

As for your second question, I assume you are talking about the free
solver called "lp_solve." I'm not sure what you mean by "embedding this
package," but in any case, I think the answer is "no." In order to use a
given third-party LP solver to solve the LP relaxations arising within
the branch and cut algorithm of SYMPHONY (if this is what you had in
mind), the solver must have an Osi interface and I do not think lp_solve
has such an interface. See

https://projects.coin-or.org/Osi

To use CPLEX in the MSVC++ environment, you need to do the following:

1. Change the preprocessor definition __OSI_CLP__ to __OSI_CPLEX__

2. Make sure the CPLEX header file is in the workspace include path, and

3. Make sure the CPLEX library is listed as an external library dependency.

Hope this helps.

Cheers,

Ted

ramana wrote:
> Hi Symphony team,
> 
> When I complied Symphony using Microsoft Visual C++ in Windows XP, I
> was getting 4 errors due to the mistake in defining  COIN_INT64_T
> variable.
> This variable is defined in
> "C:\SYMPHONY-5.1.1\BuildTools\headers\configall_system_msc.h".
> 
> This variable is defined as  "#define COIN_INT64_T long long ".
> 
> When I changed this to "#define COIN_INT64_T long ", I could compile
> successfully. Whole package is working fine.
> 
> Please correct this error in the pacakges of "SYMPHONY-5.1.0" and
> "SYMPHONY-5.1.1",  so that it will be helpful to new users.
> 
> 
> Thank you very much for providing a nice package.
> 
> Please help me regarding in embedding a "lp_solver" package.
> When I use the defalut solver of SYMPHONY for Integer Linear
> programming problem by branch and bound algorithm,   SYMPHONY solves
> the problem very slowly as compared to "lp_solver" (open source
> package).
> Is it possible to emebed this package ? If yes, please help me in this
> regard.
> 
> If I want to embed other LP solvers like Cplex and etc, what sould be
> done for invoking any of those solvers. I could not understand the
> help given in the manual.
> Please provide an easy help in this regard.
> 
> with best regards,
> Ramana
> 


-- 
Dr. Ted Ralphs
Associate Professor
Industrial and Systems Engineering
Lehigh University
(610)758-4784
tkralphs at lehigh.edu
www.lehigh.edu/~tkr2