Example #1
0
    def solve(self, *args, **kwds):
        """
        Solve a model via the GAMS Python API.

        Keyword Arguments
        -----------------
        tee=False: bool
            Output GAMS log to stdout.
        logfile=None: str
            Filename to output GAMS log to a file.
        load_solutions=True: bool
            Load solution into model. If False, the results
            object will contain the solution data.
        keepfiles=False: bool
            Keep temporary files. Equivalent of DebugLevel.KeepFiles.
            Summary of temp files can be found in _gams_py_gjo0.pf
        tmpdir=None: str
            Specify directory path for storing temporary files.
            A directory will be created if one of this name doesn't exist.
            By default uses the system default temporary path.
        report_timing=False: bool
            Print timing reports for presolve, solver, postsolve, etc.
        io_options: dict
            Options that get passed to the writer.
            See writer in pyomo.repn.plugins.gams_writer for details.
            Updated with any other keywords passed to solve method.
        """

        # Make sure available() doesn't crash
        self.available()

        from gams import GamsWorkspace, DebugLevel
        from gams.workspace import GamsExceptionExecution

        if len(args) != 1:
            raise ValueError('Exactly one model must be passed '
                             'to solve method of GAMSSolver.')
        model = args[0]

        # self.options are default for each run, overwritten by kwds
        options = dict()
        options.update(self.options)
        options.update(kwds)

        load_solutions = options.pop("load_solutions", True)
        tee = options.pop("tee", False)
        logfile = options.pop("logfile", None)
        keepfiles = options.pop("keepfiles", False)
        tmpdir = options.pop("tmpdir", None)
        report_timing = options.pop("report_timing", False)
        io_options = options.pop("io_options", {})

        # Pass remaining keywords to writer, which will handle
        # any unrecognized arguments
        io_options.update(options)

        initial_time = time.time()

        ####################################################################
        # Presolve
        ####################################################################

        # Create StringIO stream to pass to gams_writer, on which the
        # model file will be written. The writer also passes this StringIO
        # back, but output_file is defined in advance for clarity.
        output_file = StringIO()
        if isinstance(model, IBlock):
            # Kernel blocks have slightly different write method
            smap_id = model.write(filename=output_file,
                                  format=ProblemFormat.gams,
                                  _called_by_solver=True,
                                  **io_options)
            symbolMap = getattr(model, "._symbol_maps")[smap_id]
        else:
            (_, smap_id) = model.write(filename=output_file,
                                       format=ProblemFormat.gams,
                                       io_options=io_options)
            symbolMap = model.solutions.symbol_map[smap_id]

        presolve_completion_time = time.time()
        if report_timing:
            print("      %6.2f seconds required for presolve" %
                  (presolve_completion_time - initial_time))

        ####################################################################
        # Apply solver
        ####################################################################

        # IMPORTANT - only delete the whole tmpdir if the solver was the one
        # that made the directory. Otherwise, just delete the files the solver
        # made, if not keepfiles. That way the user can select a directory
        # they already have, like the current directory, without having to
        # worry about the rest of the contents of that directory being deleted.
        newdir = True
        if tmpdir is not None and os.path.exists(tmpdir):
            newdir = False

        ws = GamsWorkspace(
            debug=DebugLevel.KeepFiles if keepfiles else DebugLevel.Off,
            working_directory=tmpdir)

        t1 = ws.add_job_from_string(output_file.getvalue())

        try:
            with OutputStream(tee=tee, logfile=logfile) as output_stream:
                t1.run(output=output_stream)
        except GamsExceptionExecution as e:
            try:
                if e.rc == 3:
                    # Execution Error
                    check_expr_evaluation(model, symbolMap, 'direct')
            finally:
                # Always name working directory or delete files,
                # regardless of any errors.
                if keepfiles:
                    print("\nGAMS WORKING DIRECTORY: %s\n" %
                          ws.working_directory)
                elif tmpdir is not None:
                    # Garbage collect all references to t1.out_db
                    # So that .gdx file can be deleted
                    t1 = rec = rec_lo = rec_hi = None
                    file_removal_gams_direct(tmpdir, newdir)
                raise
        except:
            # Catch other errors and remove files first
            if keepfiles:
                print("\nGAMS WORKING DIRECTORY: %s\n" % ws.working_directory)
            elif tmpdir is not None:
                # Garbage collect all references to t1.out_db
                # So that .gdx file can be deleted
                t1 = rec = rec_lo = rec_hi = None
                file_removal_gams_direct(tmpdir, newdir)
            raise

        solve_completion_time = time.time()
        if report_timing:
            print("      %6.2f seconds required for solver" %
                  (solve_completion_time - presolve_completion_time))

        ####################################################################
        # Postsolve
        ####################################################################

        # import suffixes must be on the top-level model
        if isinstance(model, IBlock):
            model_suffixes = list(comp.storage_key for comp \
                                  in pyomo.core.kernel.suffix.\
                                  import_suffix_generator(model,
                                                          active=True,
                                                          descend_into=False))
        else:
            model_suffixes = list(name for (name,comp) \
                                  in pyomo.core.base.suffix.\
                                  active_import_suffix_generator(model))
        extract_dual = ('dual' in model_suffixes)
        extract_rc = ('rc' in model_suffixes)

        results = SolverResults()
        results.problem.name = t1.name
        results.problem.lower_bound = t1.out_db["OBJEST"].find_record().value
        results.problem.upper_bound = t1.out_db["OBJEST"].find_record().value
        results.problem.number_of_variables = \
            t1.out_db["NUMVAR"].find_record().value
        results.problem.number_of_constraints = \
            t1.out_db["NUMEQU"].find_record().value
        results.problem.number_of_nonzeros = \
            t1.out_db["NUMNZ"].find_record().value
        results.problem.number_of_binary_variables = None
        # Includes binary vars:
        results.problem.number_of_integer_variables = \
            t1.out_db["NUMDVAR"].find_record().value
        results.problem.number_of_continuous_variables = \
            t1.out_db["NUMVAR"].find_record().value \
            - t1.out_db["NUMDVAR"].find_record().value
        results.problem.number_of_objectives = 1  # required by GAMS writer
        obj = list(model.component_data_objects(Objective, active=True))
        assert len(obj) == 1, 'Only one objective is allowed.'
        obj = obj[0]
        objctvval = t1.out_db["OBJVAL"].find_record().value
        if obj.is_minimizing():
            results.problem.sense = ProblemSense.minimize
            results.problem.upper_bound = objctvval
        else:
            results.problem.sense = ProblemSense.maximize
            results.problem.lower_bound = objctvval

        results.solver.name = "GAMS " + str(self.version())

        # Init termination condition to None to give preference to this first
        # block of code, only set certain TC's below if it's still None
        results.solver.termination_condition = None
        results.solver.message = None

        solvestat = t1.out_db["SOLVESTAT"].find_record().value
        if solvestat == 1:
            results.solver.status = SolverStatus.ok
        elif solvestat == 2:
            results.solver.status = SolverStatus.ok
            results.solver.termination_condition = TerminationCondition.maxIterations
        elif solvestat == 3:
            results.solver.status = SolverStatus.ok
            results.solver.termination_condition = TerminationCondition.maxTimeLimit
        elif solvestat == 5:
            results.solver.status = SolverStatus.ok
            results.solver.termination_condition = TerminationCondition.maxEvaluations
        elif solvestat == 7:
            results.solver.status = SolverStatus.aborted
            results.solver.termination_condition = TerminationCondition.licensingProblems
        elif solvestat == 8:
            results.solver.status = SolverStatus.aborted
            results.solver.termination_condition = TerminationCondition.userInterrupt
        elif solvestat == 10:
            results.solver.status = SolverStatus.error
            results.solver.termination_condition = TerminationCondition.solverFailure
        elif solvestat == 11:
            results.solver.status = SolverStatus.error
            results.solver.termination_condition = TerminationCondition.internalSolverError
        elif solvestat == 4:
            results.solver.status = SolverStatus.warning
            results.solver.message = "Solver quit with a problem (see LST file)"
        elif solvestat in (9, 12, 13):
            results.solver.status = SolverStatus.error
        elif solvestat == 6:
            results.solver.status = SolverStatus.unknown

        results.solver.return_code = 0
        # Not sure if this value is actually user time
        # "the elapsed time it took to execute a solve statement in total"
        results.solver.user_time = t1.out_db["ETSOLVE"].find_record().value
        results.solver.system_time = None
        results.solver.wallclock_time = None
        results.solver.termination_message = None

        soln = Solution()

        modelstat = t1.out_db["MODELSTAT"].find_record().value
        if modelstat == 1:
            results.solver.termination_condition = TerminationCondition.optimal
            soln.status = SolutionStatus.optimal
        elif modelstat == 2:
            results.solver.termination_condition = TerminationCondition.locallyOptimal
            soln.status = SolutionStatus.locallyOptimal
        elif modelstat in [3, 18]:
            results.solver.termination_condition = TerminationCondition.unbounded
            soln.status = SolutionStatus.unbounded
        elif modelstat in [4, 5, 6, 10, 19]:
            results.solver.termination_condition = TerminationCondition.infeasible
            soln.status = SolutionStatus.infeasible
        elif modelstat == 7:
            results.solver.termination_condition = TerminationCondition.feasible
            soln.status = SolutionStatus.feasible
        elif modelstat == 8:
            # 'Integer solution model found'
            results.solver.termination_condition = TerminationCondition.optimal
            soln.status = SolutionStatus.optimal
        elif modelstat == 9:
            results.solver.termination_condition = TerminationCondition.intermediateNonInteger
            soln.status = SolutionStatus.other
        elif modelstat == 11:
            # Should be handled above, if modelstat and solvestat both
            # indicate a licensing problem
            if results.solver.termination_condition is None:
                results.solver.termination_condition = TerminationCondition.licensingProblems
            soln.status = SolutionStatus.error
        elif modelstat in [12, 13]:
            if results.solver.termination_condition is None:
                results.solver.termination_condition = TerminationCondition.error
            soln.status = SolutionStatus.error
        elif modelstat == 14:
            if results.solver.termination_condition is None:
                results.solver.termination_condition = TerminationCondition.noSolution
            soln.status = SolutionStatus.unknown
        elif modelstat in [15, 16, 17]:
            # Having to do with CNS models,
            # not sure what to make of status descriptions
            results.solver.termination_condition = TerminationCondition.optimal
            soln.status = SolutionStatus.unsure
        else:
            # This is just a backup catch, all cases are handled above
            soln.status = SolutionStatus.error

        soln.gap = abs(results.problem.upper_bound \
                       - results.problem.lower_bound)

        for sym, ref in iteritems(symbolMap.bySymbol):
            obj = ref()
            if isinstance(model, IBlock):
                # Kernel variables have no 'parent_component'
                if obj.ctype is IObjective:
                    soln.objective[sym] = {'Value': objctvval}
                if obj.ctype is not IVariable:
                    continue
            else:
                if obj.parent_component().type() is Objective:
                    soln.objective[sym] = {'Value': objctvval}
                if obj.parent_component().type() is not Var:
                    continue
            rec = t1.out_db[sym].find_record()
            # obj.value = rec.level
            soln.variable[sym] = {"Value": rec.level}
            if extract_rc and not math.isnan(rec.marginal):
                # Do not set marginals to nan
                # model.rc[obj] = rec.marginal
                soln.variable[sym]['rc'] = rec.marginal

        if extract_dual:
            for c in model.component_data_objects(Constraint, active=True):
                if c.body.is_fixed() or \
                   (not (c.has_lb() or c.has_ub())):
                    # the constraint was not sent to GAMS
                    continue
                sym = symbolMap.getSymbol(c)
                if c.equality:
                    rec = t1.out_db[sym].find_record()
                    if not math.isnan(rec.marginal):
                        # model.dual[c] = rec.marginal
                        soln.constraint[sym] = {'dual': rec.marginal}
                    else:
                        # Solver didn't provide marginals,
                        # nothing else to do here
                        break
                else:
                    # Inequality, assume if 2-sided that only
                    # one side's marginal is nonzero
                    # Negate marginal for _lo equations
                    marg = 0
                    if c.lower is not None:
                        rec_lo = t1.out_db[sym + '_lo'].find_record()
                        marg -= rec_lo.marginal
                    if c.upper is not None:
                        rec_hi = t1.out_db[sym + '_hi'].find_record()
                        marg += rec_hi.marginal
                    if not math.isnan(marg):
                        # model.dual[c] = marg
                        soln.constraint[sym] = {'dual': marg}
                    else:
                        # Solver didn't provide marginals,
                        # nothing else to do here
                        break

        results.solution.insert(soln)

        if keepfiles:
            print("\nGAMS WORKING DIRECTORY: %s\n" % ws.working_directory)
        elif tmpdir is not None:
            # Garbage collect all references to t1.out_db
            # So that .gdx file can be deleted
            t1 = rec = rec_lo = rec_hi = None
            file_removal_gams_direct(tmpdir, newdir)

        ####################################################################
        # Finish with results
        ####################################################################

        results._smap_id = smap_id
        results._smap = None
        if isinstance(model, IBlock):
            if len(results.solution) == 1:
                results.solution(0).symbol_map = \
                    getattr(model, "._symbol_maps")[results._smap_id]
                results.solution(0).default_variable_value = \
                    self._default_variable_value
                if load_solutions:
                    model.load_solution(results.solution(0))
            else:
                assert len(results.solution) == 0
            # see the hack in the write method
            # we don't want this to stick around on the model
            # after the solve
            assert len(getattr(model, "._symbol_maps")) == 1
            delattr(model, "._symbol_maps")
            del results._smap_id
            if load_solutions and \
               (len(results.solution) == 0):
                logger.error("No solution is available")
        else:
            if load_solutions:
                model.solutions.load_from(results)
                results._smap_id = None
                results.solution.clear()
            else:
                results._smap = model.solutions.symbol_map[smap_id]
                model.solutions.delete_symbol_map(smap_id)

        postsolve_completion_time = time.time()
        if report_timing:
            print("      %6.2f seconds required for postsolve" %
                  (postsolve_completion_time - solve_completion_time))
            print("      %6.2f seconds required total" %
                  (postsolve_completion_time - initial_time))

        return results
Example #2
0
    def solve(self, *args, **kwds):
        """
        Uses GAMS Python API. For installation help visit:
        https://www.gams.com/latest/docs/apis/examples_python/index.html

        tee=False:
            Output GAMS log to stdout.
        load_solutions=True:
            Does not support load_solutions=False.
        keepfiles=False:
            Keep temporary files. Equivalent of DebugLevel.KeepFiles.
            Summary of temp files can be found in _gams_py_gjo0.pf
        tmpdir=None:
            Specify directory path for storing temporary files.
            A directory will be created if one of this name doesn't exist.
        io_options:
            Updated with additional keywords passed to solve()
            warmstart=False:
                Warmstart by initializing model's variables to their values.
            symbolic_solver_labels=False:
                Use full Pyomo component names rather than
                shortened symbols (slower, but useful for debugging).
            labeler=None:
                Custom labeler option. Incompatible with symbolic_solver_labels.
            solver=None:
                If None, GAMS will use default solver for model type.
            mtype=None:
                Model type. If None, will chose from lp, nlp, mip, and minlp.
            add_options=None:
                List of additional lines to write directly
                into model file before the solve statement.
                For model attributes, <model name> is GAMS_MODEL.
            skip_trivial_constraints=False:
                Skip writing constraints whose body section is fixed
            file_determinism=1:
                How much effort do we want to put into ensuring the
                LP file is written deterministically for a Pyomo model:
                   0 : None
                   1 : sort keys of indexed components (default)
                   2 : sort keys AND sort names (over declaration order)
            put_results=None:
                Filename for optionally writing solution values and
                marginals to (put_results).dat, and solver statuses
                to (put_results + 'stat').dat.
        """

        # Make sure available() doesn't crash
        self.available()

        from gams import GamsWorkspace, DebugLevel
        from gams.workspace import GamsExceptionExecution

        if len(args) != 1:
            raise ValueError('Exactly one model must be passed '
                             'to solve method of GAMSSolver.')
        model = args[0]

        load_solutions = kwds.pop("load_solutions", True)
        tee = kwds.pop("tee", False)
        keepfiles = kwds.pop("keepfiles", False)
        tmpdir = kwds.pop("tmpdir", None)
        io_options = kwds.pop("io_options", {})

        if len(kwds):
            # Pass remaining keywords to writer, which will handle
            # any unrecognized arguments
            io_options.update(kwds)

        ####################################################################
        # Presolve
        ####################################################################

        # Create StringIO stream to pass to gams_writer, on which the
        # model file will be written. The writer also passes this StringIO
        # back, but output_file is defined in advance for clarity.
        output_file = StringIO()
        if isinstance(model, IBlockStorage):
            # Kernel blocks have slightly different write method
            smap_id = model.write(filename=output_file,
                                  format=ProblemFormat.gams,
                                  _called_by_solver=True,
                                  **io_options)
            symbolMap = getattr(model, "._symbol_maps")[smap_id]
        else:
            (_, smap_id) = model.write(filename=output_file,
                                       format=ProblemFormat.gams,
                                       io_options=io_options)
            symbolMap = model.solutions.symbol_map[smap_id]

        ####################################################################
        # Apply solver
        ####################################################################

        # IMPORTANT - only delete the whole tmpdir if the solver was the one
        # that made the directory. Otherwise, just delete the files the solver
        # made, if not keepfiles. That way the user can select a directory
        # they already have, like the current directory, without having to
        # worry about the rest of the contents of that directory being deleted.
        newdir = True
        if tmpdir is not None and os.path.exists(tmpdir):
            newdir = False

        ws = GamsWorkspace(
            debug=DebugLevel.KeepFiles if keepfiles else DebugLevel.Off,
            working_directory=tmpdir)

        t1 = ws.add_job_from_string(output_file.getvalue())

        try:
            t1.run(output=sys.stdout if tee else None)
        except GamsExceptionExecution:
            try:
                check_expr_evaluation(model, symbolMap, 'direct')
            finally:
                # Always name working directory or delete files,
                # regardless of any errors.
                if keepfiles:
                    print("\nGAMS WORKING DIRECTORY: %s\n" %
                          ws.working_directory)
                elif tmpdir is not None:
                    # Garbage collect all references to t1.out_db
                    # So that .gdx file can be deleted
                    t1 = rec = rec_lo = rec_hi = None
                    file_removal_gams_direct(tmpdir, newdir)
                raise
        except:
            # Catch other errors and remove files first
            if keepfiles:
                print("\nGAMS WORKING DIRECTORY: %s\n" % ws.working_directory)
            elif tmpdir is not None:
                # Garbage collect all references to t1.out_db
                # So that .gdx file can be deleted
                t1 = rec = rec_lo = rec_hi = None
                file_removal_gams_direct(tmpdir, newdir)
            raise

        ####################################################################
        # Postsolve
        ####################################################################

        # import suffixes must be on the top-level model
        if isinstance(model, IBlockStorage):
            model_suffixes = list(name for (name,comp) \
                                  in pyomo.core.kernel.component_suffix.\
                                  import_suffix_generator(model,
                                                          active=True,
                                                          descend_into=False,
                                                          return_key=True))
        else:
            model_suffixes = list(name for (name,comp) \
                                  in pyomo.core.base.suffix.\
                                  active_import_suffix_generator(model))
        extract_dual = ('dual' in model_suffixes)
        extract_rc = ('rc' in model_suffixes)

        results = SolverResults()
        results.problem.name = t1.name
        results.problem.lower_bound = t1.out_db["OBJEST"].find_record().value
        results.problem.upper_bound = t1.out_db["OBJEST"].find_record().value
        results.problem.number_of_variables = \
            t1.out_db["NUMVAR"].find_record().value
        results.problem.number_of_constraints = \
            t1.out_db["NUMEQU"].find_record().value
        results.problem.number_of_nonzeros = \
            t1.out_db["NUMNZ"].find_record().value
        results.problem.number_of_binary_variables = None
        # Includes binary vars:
        results.problem.number_of_integer_variables = \
            t1.out_db["NUMDVAR"].find_record().value
        results.problem.number_of_continuous_variables = \
            t1.out_db["NUMVAR"].find_record().value \
            - t1.out_db["NUMDVAR"].find_record().value
        results.problem.number_of_objectives = 1  # required by GAMS writer
        obj = list(model.component_data_objects(Objective, active=True))
        assert len(obj) == 1, 'Only one objective is allowed.'
        obj = obj[0]
        objctvval = t1.out_db["OBJVAL"].find_record().value
        if obj.is_minimizing():
            results.problem.sense = ProblemSense.minimize
            results.problem.upper_bound = objctvval
        else:
            results.problem.sense = ProblemSense.maximize
            results.problem.lower_bound = objctvval

        results.solver.name = "GAMS " + str(self.version())

        # Init termination condition to None to give preference to this first
        # block of code, only set certain TC's below if it's still None
        results.solver.termination_condition = None
        results.solver.message = None

        solvestat = t1.out_db["SOLVESTAT"].find_record().value
        if solvestat == 1:
            results.solver.status = SolverStatus.ok
        elif solvestat == 2:
            results.solver.status = SolverStatus.ok
            results.solver.termination_condition = TerminationCondition.maxIterations
        elif solvestat == 3:
            results.solver.status = SolverStatus.ok
            results.solver.termination_condition = TerminationCondition.maxTimeLimit
        elif solvestat == 5:
            results.solver.status = SolverStatus.ok
            results.solver.termination_condition = TerminationCondition.maxEvaluations
        elif solvestat == 7:
            results.solver.status = SolverStatus.aborted
            results.solver.termination_condition = TerminationCondition.licensingProblems
        elif solvestat == 8:
            results.solver.status = SolverStatus.aborted
            results.solver.termination_condition = TerminationCondition.userInterrupt
        elif solvestat == 10:
            results.solver.status = SolverStatus.error
            results.solver.termination_condition = TerminationCondition.solverFailure
        elif solvestat == 11:
            results.solver.status = SolverStatus.error
            results.solver.termination_condition = TerminationCondition.internalSolverError
        elif solvestat == 4:
            results.solver.status = SolverStatus.warning
            results.solver.message = "Solver quit with a problem (see LST file)"
        elif solvestat in (9, 12, 13):
            results.solver.status = SolverStatus.error
        elif solvestat == 6:
            results.solver.status = SolverStatus.unknown

        results.solver.return_code = 0
        # Not sure if this value is actually user time
        # "the elapsed time it took to execute a solve statement in total"
        results.solver.user_time = t1.out_db["ETSOLVE"].find_record().value
        results.solver.system_time = None
        results.solver.wallclock_time = None
        results.solver.termination_message = None

        soln = Solution()

        modelstat = t1.out_db["MODELSTAT"].find_record().value
        if modelstat == 1:
            results.solver.termination_condition = TerminationCondition.optimal
            soln.status = SolutionStatus.optimal
        elif modelstat == 2:
            results.solver.termination_condition = TerminationCondition.locallyOptimal
            soln.status = SolutionStatus.locallyOptimal
        elif modelstat in [3, 18]:
            results.solver.termination_condition = TerminationCondition.unbounded
            soln.status = SolutionStatus.unbounded
        elif modelstat in [4, 5, 6, 10, 19]:
            results.solver.termination_condition = TerminationCondition.infeasible
            soln.status = SolutionStatus.infeasible
        elif modelstat == 7:
            results.solver.termination_condition = TerminationCondition.feasible
            soln.status = SolutionStatus.feasible
        elif modelstat == 8:
            # 'Integer solution model found'
            results.solver.termination_condition = TerminationCondition.optimal
            soln.status = SolutionStatus.optimal
        elif modelstat == 9:
            results.solver.termination_condition = TerminationCondition.intermediateNonInteger
            soln.status = SolutionStatus.other
        elif modelstat == 11:
            # Should be handled above, if modelstat and solvestat both
            # indicate a licensing problem
            if results.solver.termination_condition is None:
                results.solver.termination_condition = TerminationCondition.licensingProblems
            soln.status = SolutionStatus.error
        elif modelstat in [12, 13]:
            if results.solver.termination_condition is None:
                results.solver.termination_condition = TerminationCondition.error
            soln.status = SolutionStatus.error
        elif modelstat == 14:
            if results.solver.termination_condition is None:
                results.solver.termination_condition = TerminationCondition.noSolution
            soln.status = SolutionStatus.unknown
        elif modelstat in [15, 16, 17]:
            # Having to do with CNS models,
            # not sure what to make of status descriptions
            results.solver.termination_condition = TerminationCondition.optimal
            soln.status = SolutionStatus.unsure
        else:
            # This is just a backup catch, all cases are handled above
            soln.status = SolutionStatus.error

        soln.gap = abs(results.problem.upper_bound \
                       - results.problem.lower_bound)

        for sym, ref in iteritems(symbolMap.bySymbol):
            obj = ref()
            if isinstance(model, IBlockStorage):
                # Kernel variables have no 'parent_component'
                if obj.ctype is Objective:
                    soln.objective[sym] = {'Value': objctvval}
                if obj.ctype is not Var:
                    continue
            else:
                if obj.parent_component().type() is Objective:
                    soln.objective[sym] = {'Value': objctvval}
                if obj.parent_component().type() is not Var:
                    continue
            rec = t1.out_db[sym].find_record()
            # obj.value = rec.level
            soln.variable[sym] = {"Value": rec.level}
            if extract_rc and not math.isnan(rec.marginal):
                # Do not set marginals to nan
                # model.rc[obj] = rec.marginal
                soln.variable[sym]['rc'] = rec.marginal

        if extract_dual:
            for c in model.component_data_objects(Constraint, active=True):
                if c.body.is_fixed():
                    continue
                sym = symbolMap.getSymbol(c)
                if c.equality:
                    rec = t1.out_db[sym].find_record()
                    if not math.isnan(rec.marginal):
                        # model.dual[c] = rec.marginal
                        soln.constraint[sym] = {'dual': rec.marginal}
                    else:
                        # Solver didn't provide marginals,
                        # nothing else to do here
                        break
                else:
                    # Inequality, assume if 2-sided that only
                    # one side's marginal is nonzero
                    # Negate marginal for _lo equations
                    marg = 0
                    if c.lower is not None:
                        rec_lo = t1.out_db[sym + '_lo'].find_record()
                        marg -= rec_lo.marginal
                    if c.upper is not None:
                        rec_hi = t1.out_db[sym + '_hi'].find_record()
                        marg += rec_hi.marginal
                    if not math.isnan(marg):
                        # model.dual[c] = marg
                        soln.constraint[sym] = {'dual': marg}
                    else:
                        # Solver didn't provide marginals,
                        # nothing else to do here
                        break

        results.solution.insert(soln)

        if keepfiles:
            print("\nGAMS WORKING DIRECTORY: %s\n" % ws.working_directory)
        elif tmpdir is not None:
            # Garbage collect all references to t1.out_db
            # So that .gdx file can be deleted
            t1 = rec = rec_lo = rec_hi = None
            file_removal_gams_direct(tmpdir, newdir)

        ####################################################################
        # Finish with results
        ####################################################################

        results._smap_id = smap_id
        results._smap = None
        if isinstance(model, IBlockStorage):
            if len(results.solution) == 1:
                results.solution(0).symbol_map = \
                    getattr(model, "._symbol_maps")[results._smap_id]
                results.solution(0).default_variable_value = \
                    self._default_variable_value
                if load_solutions:
                    model.load_solution(results.solution(0))
                    results.solution.clear()
            else:
                assert len(results.solution) == 0
            # see the hack in the write method
            # we don't want this to stick around on the model
            # after the solve
            assert len(getattr(model, "._symbol_maps")) == 1
            delattr(model, "._symbol_maps")
            del results._smap_id
        else:
            if load_solutions:
                model.solutions.load_from(results)
                results._smap_id = None
                results.solution.clear()
            else:
                results._smap = model.solutions.symbol_map[smap_id]
                model.solutions.delete_symbol_map(smap_id)

        return results