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debugginglinear-programminghuman-readableglpk

Print GLPK objective/constraints in human readable format

I'm using GLPK C API for a mixed integer programming problem. Is there some way to print the objective/constraints in human readable format for debugging?

Solution

  • Perhaps the nicest format is the CPLEX LP format. It looks something like this:

    Maximize
    obj: x1 + 2 x2 + 3 x3 + x4
    Subject To
    c1: - x1 + x2 + x3 + 10 x4 <= 20
    c2: x1 - 3 x2 + x3 <= 30
    c3: x2 - 3.5 x4 = 0
    Bounds
    0 <= x1 <= 40
    2 <= x4 <= 3
    General
    x4
    End

    You can write your model in this format by calling:

    int glp_write_lp(glp_prob *P, const glp_cpxcp *parm, const char *fname);

    See also glp_write_lp — write problem data in CPLEX LP format in the documentation that comes with GLPK.