[Coin-discuss] does CGL depend on CLP?

[Laszlo Ladanyi]

On Thu, 21 May 2009, Matthew Galati wrote:

> I am trying to use CPLEX as my LP solver. Does CGL depend on CLP? if 
> so - why? CGL should be completely independent of any LP solver - 
> right?

Yes and no... The end result is independent. However, some cut 
generators (e.g., CglLandP) depend on being able to perform low level 
tableau manipulation. Those methods are not available through OSI, so 
the cut generator uses an LP solver that does support these functions, 
and clp is a natural choice there. Actually, even if those methods 
would be available through OSI some LP solvers (like interior point) 
do not support them, so CGL would have to link with clp (or some LP 
solver that does support tableau methods) as a backup solution.

Granted, the code could have been written with a bunch of ifdefs, but 
apparently that's not how it was done...

--Laci

>
>
> bla=;\
>        for file in ATM_Main.o ATM_Instance.o ATM_DecompApp.o; do bla="$bla `echo $file`"; done; \
>        g++ -Wl,--rpath -Wl,/home/magh/COIN/coin-Decomp/build/lib -O3 -fomit-frame-pointer -pipe -DNDEBUG -pedantic-errors -Wimplicit -Wparentheses -Wreturn-type -Wcast-qual -Wall -Wpointer-arith -Wwrite-strings -Wconversion -Wno-unknown-pragmas   -o decomp_atm $bla  -L/home/magh/COIN/coin-Decomp/build/lib -lDecomp -L/usr/local/cplex/lib/x86_rhel4.0_3.4/static_pic -lcplex -lpthread -lm  -lAlps `cat /home/magh/COIN/coin-Decomp/build/Decomp/../Alps/alps_addlibs.txt` -lOsiCpx -lcplex -lOsiCpx -lcplex -L/home/magh/COIN/coin-Decomp/build/lib -lCgl -lOsi -lCoinUtils `cat /home/magh/COIN/coin-Decomp/build/Decomp/../Cgl/cgl_addlibs.txt` `cat /home/magh/COIN/coin-Decomp/build/Decomp/../Osi/osi_addlibs.txt` `cat /home/magh/COIN/coin-Decomp/build/Decomp/../CoinUtils/coinutils_addlibs.txt`
> /home/magh/COIN/coin-Decomp/build/lib/libCgl.so: undefined reference to `typeinfo for OsiClpSolverInterface'
> /home/magh/COIN/coin-Decomp/build/lib/libCgl.so: undefined reference to `OsiClpSolverInterface::getModelPtr() const'
> /home/magh/COIN/coin-Decomp/build/lib/libCgl.so: undefined reference to `ClpSimplex::factorize()'
> collect2: ld returned 1 exit status
> make: *** [decomp_atm] Error 1
>