solveByCplex.py

from __future__ import print_function
import sys
import cplex
from cplex.exceptions import CplexSolverError

def Solve(filename):
    c = cplex.Cplex(filename)

    try:
        #c.set_results_stream(None)#close display
        c.parameters.mip.tolerances.absmipgap.set(0)
        c.solve()
    except CplexSolverError:
        print("Exception raised during solve")
        return

    # solution.get_status() returns an integer code
    status = c.solution.get_status()
    print(c.solution.status[status])
    if status == c.solution.status.unbounded:
        print("Model is unbounded")
        return
    if status == c.solution.status.infeasible:
        print("Model is infeasible")
        return
    if status == c.solution.status.infeasible_or_unbounded:
        print("Model is infeasible or unbounded")
        return

    s_method = c.solution.get_method()

    s_type = c.solution.get_solution_type()

    print("Solution status = ", status, ":", end=' ')
    # the following line prints the status as a string
    print(c.solution.status[status])

    if s_type == c.solution.type.none:
        print("No solution available")
        return
    print("Objective value = ", c.solution.get_objective_value())

    print()

    x = c.solution.get_values(0, c.variables.get_num() - 1)
    # because we're querying the entire solution vector,
    # x = c.solution.get_values()
    # would have the same effect
    #for j in range(c.variables.get_num()):
    #    if x[j]==1:
    #        print("Column %d: Value = %17.10g" % (j, x[j]))

#if __name__ == "__main__":
#    if len(sys.argv) != 2:
#        print("Usage: mipex2.py filename")
#        print("  filename   Name of a file, with .mps, .lp, or .sav")
#        print("             extension, and a possible, additional .gz")
#        print("             extension")
#        sys.exit(-1)
#    mipex2(sys.argv[1])