Custom Query (545 matches)

In MipSolver there are type(), sol() and solValue() functions to obtain the (primal) solution.

1. There are two inconsistent names here:
   • solValue() should be renamed to sol() (as on overloaded version) as primalValue() was renamed to primal() in LpSolver.
   • ColTypes should be renamed to ColType, since we do not use plural in similar names.

2. Apart form that, I suggest an extension. Let's introduce primalType() and primal() as an alias for the above functions. Adding these variants, one can change to using a Mip solver instead of an Lp solver without rewriting the code (if only primal queries were used).

3. Maybe type(), sol() could also be added to LpSolver as an alias for the primal queries.

The program below gives x=1, y=0 as solution with LEMON 1.1.1, but with [9cc6e98c487d] the solution is x=1, y=1 (both with Glpk and Cbc).

#include <iostream>

#include <lemon/glpk.h>
#include <lemon/cbc.h>

int main()
{
    typedef lemon::GlpkMip MIP;
    //typedef lemon::CbcMip MIP;

    MIP mip;

    MIP::Col x, y;
    x = mip.addCol();
    y = mip.addCol();

    MIP::Expr e(x - 1.0);
    mip.addRow(e <= y);

    mip.colLowerBound(y, 0.0);

    mip.colType(x, MIP::INTEGER);
    mip.colBounds(x, 1.0, 2.0);

    mip.obj(y);
    mip.min();

    if (mip.solve() != MIP::SOLVED ||
        mip.type() != MIP::OPTIMAL)
    {
        std::cout << "could not solve it" << std::endl;
        return 0;
    }

    std::cout << "x=" << mip.sol(x) << std::endl;
    std::cout << "y=" << mip.sol(y) << std::endl;

    return 0;
}

The title says everything.

Here is the related part of the build output.

	g++ -DHAVE_CONFIG_H   -I. -I.  -Wall -W -Wall -W -Wunused -Wformat=2 -Wctor-dtor-privacy -Wnon-virtual-dtor -Wno-char-subscripts -Wwrite-strings -Wno-char-subscripts -Wreturn-type -Wcast-qual -Wcast-align -Wsign-promo -Woverloaded-virtual -ansi -fno-strict-aliasing -Wold-style-cast -Wno-unknown-pragmas -ggdb -Werror -MT tools/dimacs-solver.o -MD -MP -MF $depbase.Tpo -c -o tools/dimacs-solver.o tools/dimacs-solver.cc &&\
	mv -f $depbase.Tpo $depbase.Po
In file included from lemon/glpk.cc:23:
/home/alpar/projects/LEMON/local/include/glpk.h:40: error: conflicting declaration ‘typedef struct glp_prob glp_prob’
./lemon/glpk.h:32: error: ‘glp_prob’ has a previous declaration as ‘typedef struct glp_prob glp_prob’
make[2]: *** [lemon/lemon_libemon_la-glpk.lo] Error 1
make[2]: *** Waiting for unfinished jobs....
make[2]: Leaving directory `/home/alpar/projects/LEMON/hg/main'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/home/alpar/projects/LEMON/hg/main'
make: *** [all] Error 2