예제 #1
0
파일: implicitsp.py 프로젝트: qtothec/pyomo
    def _generate_base_scenario_tree(self, model, variable_stage_assignments):

        stage_cost_annotation = locate_annotations(
            model,
            PySP_StageCostAnnotation,
            max_allowed=1)
        if len(stage_cost_annotation) == 0:
            raise ValueError("Reference model is missing stage cost "
                             "annotation: %s" % (PySP_StageCostAnnotation.__name__))
        else:
            assert len(stage_cost_annotation) == 1
            stage_cost_annotation = stage_cost_annotation[0][1]
        stage_cost_assignments = ComponentMap(
            stage_cost_annotation.expand_entries())

        stage1_cost = None
        stage2_cost = None
        for cdata, stagenum in stage_cost_assignments.items():
            if stagenum == 1:
                stage1_cost = cdata
            elif stagenum == 2:
                stage2_cost = cdata
        if stage1_cost is None:
            raise ValueError("Missing stage cost annotation for time stage: 1")
        if stage2_cost is None:
            raise ValueError("Missing stage cost annotation for time stage: 2")
        assert stage1_cost != stage2_cost

        #
        # Create a dummy 1-scenario scenario tree
        #

        stm = CreateAbstractScenarioTreeModel()
        stm.Stages.add('Stage1')
        stm.Stages.add('Stage2')
        stm.Nodes.add('RootNode')
        stm.Nodes.add('LeafNode')
        stm.Scenarios.add('ReferenceScenario')
        stm = stm.create_instance()
        stm.NodeStage['RootNode'] = 'Stage1'
        stm.ConditionalProbability['RootNode'] = 1.0
        stm.NodeStage['LeafNode'] = 'Stage2'
        stm.Children['RootNode'].add('LeafNode')
        stm.Children['LeafNode'].clear()
        stm.ConditionalProbability['LeafNode'] = 1.0
        stm.ScenarioLeafNode['ReferenceScenario'] = 'LeafNode'

        stm.StageCost['Stage1'] = stage1_cost.name
        stm.StageCost['Stage2'] = stage2_cost.name
        for var, (stagenum, derived) in variable_stage_assignments.items():
            stagelabel = 'Stage'+str(stagenum)
            if not derived:
                stm.StageVariables[stagelabel].add(var.name)
            else:
                stm.StageDerivedVariables[second_stage].add(var.name)

        scenario_tree = ScenarioTree(scenariotreeinstance=stm)
        scenario_tree.linkInInstances(
            {'ReferenceScenario': self.reference_model})
        return scenario_tree
예제 #2
0
파일: implicitsp.py 프로젝트: smars8/pyomo
    def _generate_base_scenario_tree(self, model, variable_stage_assignments):

        stage_cost_annotation = locate_annotations(model,
                                                   PySP_StageCostAnnotation,
                                                   max_allowed=1)
        if len(stage_cost_annotation) == 0:
            raise ValueError("Reference model is missing stage cost "
                             "annotation: %s" %
                             (PySP_StageCostAnnotation.__name__))
        else:
            assert len(stage_cost_annotation) == 1
            stage_cost_annotation = stage_cost_annotation[0][1]
        stage_cost_assignments = ComponentMap(
            stage_cost_annotation.expand_entries())

        stage1_cost = None
        stage2_cost = None
        for cdata, stagenum in stage_cost_assignments.items():
            if stagenum == 1:
                stage1_cost = cdata
            elif stagenum == 2:
                stage2_cost = cdata
        if stage1_cost is None:
            raise ValueError("Missing stage cost annotation for time stage: 1")
        if stage2_cost is None:
            raise ValueError("Missing stage cost annotation for time stage: 2")
        assert stage1_cost != stage2_cost

        #
        # Create a dummy 1-scenario scenario tree
        #

        stm = CreateAbstractScenarioTreeModel()
        stm.Stages.add('Stage1')
        stm.Stages.add('Stage2')
        stm.Nodes.add('RootNode')
        stm.Nodes.add('LeafNode')
        stm.Scenarios.add('ReferenceScenario')
        stm = stm.create_instance()
        stm.NodeStage['RootNode'] = 'Stage1'
        stm.ConditionalProbability['RootNode'] = 1.0
        stm.NodeStage['LeafNode'] = 'Stage2'
        stm.Children['RootNode'].add('LeafNode')
        stm.Children['LeafNode'].clear()
        stm.ConditionalProbability['LeafNode'] = 1.0
        stm.ScenarioLeafNode['ReferenceScenario'] = 'LeafNode'

        stm.StageCost['Stage1'] = stage1_cost.name
        stm.StageCost['Stage2'] = stage2_cost.name
        for var, (stagenum, derived) in variable_stage_assignments.items():
            stagelabel = 'Stage' + str(stagenum)
            if not derived:
                stm.StageVariables[stagelabel].add(var.name)
            else:
                stm.StageDerivedVariables[second_stage].add(var.name)

        scenario_tree = ScenarioTree(scenariotreeinstance=stm)
        scenario_tree.linkInInstances(
            {'ReferenceScenario': self.reference_model})
        return scenario_tree
예제 #3
0
파일: implicitsp.py 프로젝트: qtothec/pyomo
    def _map_variable_stages(self, model):

        variable_stage_annotation = locate_annotations(
            model,
            PySP_VariableStageAnnotation,
        max_allowed=1)
        if len(variable_stage_annotation) == 0:
            raise ValueError(
                "Reference model is missing variable stage "
                "annotation: %s" % (PySP_VariableStageAnnotation.__name__))
        else:
            assert len(variable_stage_annotation) == 1
            variable_stage_annotation = variable_stage_annotation[0][1]
        variable_stage_assignments = ComponentMap(
            variable_stage_annotation.expand_entries(
                expand_containers=False))
        if len(variable_stage_assignments) == 0:
            raise ValueError("At least one variable stage assignment is required.")

        min_stagenumber = min(variable_stage_assignments.values(),
                              key=lambda x: x[0])[0]
        max_stagenumber = max(variable_stage_assignments.values(),
                              key=lambda x: x[0])[0]
        if max_stagenumber > 2:
            for vardata, (stagenum, derived) in variable_stage_assignments.items():
                if stagenum > 2:
                    raise ValueError(
                        "Implicit stochastic programs must be two-stage, "
                        "but variable with name '%s' has been annotated with "
                        "stage number: %s" % (vardata.name, stagenum))

        stage_to_variables_map = {}
        stage_to_variables_map[1] = []
        stage_to_variables_map[2] = []
        for vardata in model.component_data_objects(
                Var,
                active=True,
                descend_into=True,
                sort=SortComponents.alphabetizeComponentAndIndex):
            stagenumber, derived = variable_stage_assignments.get(vardata, (2, False))
            if (stagenumber != 1) and (stagenumber != 2):
                raise ValueError("Invalid stage annotation for variable with "
                                 "name '%s'. Stage assignment must be 1 or 2. "
                                 "Current value: %s"
                                 % (vardata.name, stagenumber))
            if (stagenumber == 1):
                stage_to_variables_map[1].append((vardata, derived))
            else:
                assert stagenumber == 2
                stage_to_variables_map[2].append((vardata, derived))

        variable_to_stage_map = ComponentMap()
        for stagenum, stagevars in stage_to_variables_map.items():
            for vardata, derived in stagevars:
                variable_to_stage_map[vardata] = (stagenum, derived)

        return (stage_to_variables_map,
                variable_to_stage_map,
                variable_stage_assignments)
예제 #4
0
def _map_variable_stages(model):

    variable_stage_annotation = locate_annotations(model,
                                                   VariableStageAnnotation,
                                                   max_allowed=1)
    if len(variable_stage_annotation) == 0:
        raise ValueError("Reference model is missing variable stage "
                         "annotation: %s" % (VariableStageAnnotation.__name__))
    else:
        assert len(variable_stage_annotation) == 1
        variable_stage_annotation = variable_stage_annotation[0][1]

    variable_stage_assignments = ComponentMap(
        variable_stage_annotation.expand_entries())
    if len(variable_stage_assignments) == 0:
        raise ValueError("At least one variable stage assignment "
                         "is required.")

    min_stagenumber = min(variable_stage_assignments.values(),
                          key=lambda x: x[0])[0]
    max_stagenumber = max(variable_stage_assignments.values(),
                          key=lambda x: x[0])[0]
    if max_stagenumber > 2:
        for var, (stagenum, derived) in \
              variable_stage_assignments.items():
            if stagenum > 2:
                raise ValueError(
                    "Embedded stochastic programs must be two-stage "
                    "(for now), but variable with name '%s' has been "
                    "annotated with stage number: %s" % (var.name, stagenum))

    stage_to_variables_map = {}
    stage_to_variables_map[1] = []
    stage_to_variables_map[2] = []
    for var in model.component_data_objects(
            Var,
            active=True,
            descend_into=True,
            sort=SortComponents.alphabetizeComponentAndIndex):
        stagenumber, derived = \
            variable_stage_assignments.get(var, (2, False))
        if (stagenumber != 1) and (stagenumber != 2):
            raise ValueError("Invalid stage annotation for variable with "
                             "name '%s'. Stage assignment must be 1 or 2. "
                             "Current value: %s" % (var.name, stagenumber))
        if (stagenumber == 1):
            stage_to_variables_map[1].append((var, derived))
        else:
            assert stagenumber == 2
            stage_to_variables_map[2].append((var, derived))

    variable_to_stage_map = ComponentMap()
    for stagenum, stagevars in stage_to_variables_map.items():
        for var, derived in stagevars:
            variable_to_stage_map[var] = (stagenum, derived)

    return (stage_to_variables_map, variable_to_stage_map,
            variable_stage_assignments)
예제 #5
0
    def __init__(self, reference_model):

        self.reference_model = None
        self.objective = None
        self.time_stages = None

        self.stage_to_variables_map = {}
        self.variable_to_stage_map = {}

        # the set of stochastic data objects
        # (possibly mapped to some distribution)
        self.stochastic_data = None

        # maps between variables and objectives
        self.variable_to_objectives_map = ComponentMap()
        self.objective_to_variables_map = ComponentMap()

        # maps between variables and constraints
        self.variable_to_constraints_map = ComponentMap()
        self.constraint_to_variables_map = ComponentMap()

        # maps between stochastic data and objectives
        self.stochastic_data_to_objectives_map = ComponentMap()
        self.objective_to_stochastic_data_map = ComponentMap()

        # maps between stochastic data and constraints
        self.stochastic_data_to_constraints_map = ComponentMap()
        self.constraint_to_stochastic_data_map = ComponentMap()

        # maps between stochastic data and variable lower and upper bounds
        self.stochastic_data_to_variables_lb_map = ComponentMap()
        self.variable_to_stochastic_data_lb_map = ComponentMap()

        self.stochastic_data_to_variables_ub_map = ComponentMap()
        self.variable_to_stochastic_data_ub_map = ComponentMap()

        self.variable_symbols = ComponentMap()

        if not isinstance(reference_model, Block):
            raise TypeError("reference model input must be a Pyomo model")
        self.reference_model = reference_model

        #
        # Extract stochastic parameters from the
        # StochasticDataAnnotation object
        #
        self.stochastic_data = \
            _extract_stochastic_data(self.reference_model)

        #
        # Get the variable stages from the
        # VariableStageAnnotation object
        #
        (self.stage_to_variables_map,
         self.variable_to_stage_map,
         self._variable_stage_assignments) = \
            _map_variable_stages(self.reference_model)
        self.time_stages = tuple(sorted(self.stage_to_variables_map))
        assert self.time_stages[0] == 1
        self.variable_symbols = generate_cuid_names(self.reference_model,
                                                    ctype=Var)
        # remove the parent blocks from this map
        keys_to_delete = []
        for var in self.variable_symbols:
            if var.parent_component().ctype is not Var:
                keys_to_delete.append(var)
        for key in keys_to_delete:
            del self.variable_symbols[key]

        #
        # Get the stage cost components from the StageCostAnnotation
        # and generate a dummy single-scenario scenario tree
        #
        stage_cost_annotation = locate_annotations(self.reference_model,
                                                   StageCostAnnotation,
                                                   max_allowed=1)
        if len(stage_cost_annotation) == 0:
            raise ValueError("Reference model is missing stage cost "
                             "annotation: %s" % (StageCostAnnotation.__name__))
        else:
            assert len(stage_cost_annotation) == 1
            stage_cost_annotation = stage_cost_annotation[0][1]
        stage_cost_assignments = ComponentMap(
            stage_cost_annotation.expand_entries())

        stage1_cost = None
        stage2_cost = None
        for cdata, stagenum in stage_cost_assignments.items():
            if stagenum == 1:
                stage1_cost = cdata
            elif stagenum == 2:
                stage2_cost = cdata
        if stage1_cost is None:
            raise ValueError("Missing stage cost annotation "
                             "for time stage: 1")
        if stage2_cost is None:
            raise ValueError("Missing stage cost annotation "
                             "for time stage: 2")
        assert stage1_cost is not stage2_cost
        self._stage1_cost = stage1_cost
        self._stage2_cost = stage2_cost

        #
        # Extract the locations of variables and stochastic data
        # within the model
        #
        sto_obj = StochasticObjectiveAnnotation()
        for objcntr, obj in enumerate(
                self.reference_model.component_data_objects(Objective,
                                                            active=True,
                                                            descend_into=True),
                1):

            if objcntr > 1:
                raise ValueError(
                    "Reference model can not contain more than one "
                    "active objective")

            self.objective = obj
            self.objective_sense = obj.sense

            obj_params = tuple(
                self._collect_mutable_parameters(obj.expr).values())
            self.objective_to_stochastic_data_map[obj] = []
            for paramdata in obj_params:
                if paramdata in self.stochastic_data:
                    self.stochastic_data_to_objectives_map.\
                        setdefault(paramdata, []).append(obj)
                    self.objective_to_stochastic_data_map[obj].\
                        append(paramdata)
            if len(self.objective_to_stochastic_data_map[obj]) == 0:
                del self.objective_to_stochastic_data_map[obj]
            else:
                # TODO: Can we make this declaration sparse
                #       by identifying which variables have
                #       stochastic coefficients? How to handle
                #       non-linear expressions?
                sto_obj.declare(obj)

            obj_variables = tuple(self._collect_variables(obj.expr).values())
            self.objective_to_variables_map[obj] = []
            for var in obj_variables:
                self.variable_to_objectives_map.\
                    setdefault(var, []).append(obj)
                self.objective_to_variables_map[obj].append(var)
            if len(self.objective_to_variables_map[obj]) == 0:
                del self.objective_to_variables_map[obj]

        sto_conbounds = StochasticConstraintBoundsAnnotation()
        sto_conbody = StochasticConstraintBodyAnnotation()
        for con in self.reference_model.component_data_objects(
                Constraint, active=True, descend_into=True):

            lower_params = tuple(
                self._collect_mutable_parameters(con.lower).values())
            body_params = tuple(
                self._collect_mutable_parameters(con.body).values())
            upper_params = tuple(
                self._collect_mutable_parameters(con.upper).values())

            # TODO: Can we make this declaration sparse
            #       by idenfifying which variables have
            #       stochastic coefficients? How to handle
            #       non-linear expressions? Currently, this
            #       code also fails to detect that mutable
            #       "constant" expressions might fall out
            #       of the body and into the bounds.
            if len(body_params):
                sto_conbody.declare(con)
            if len(body_params) or \
               len(lower_params) or \
               len(upper_params):
                sto_conbounds.declare(
                    con,
                    lb=bool(len(lower_params) or len(body_params)),
                    ub=bool(len(upper_params) or len(body_params)))

            all_stochastic_params = {}
            for param in itertools.chain(lower_params, body_params,
                                         upper_params):
                if param in self.stochastic_data:
                    all_stochastic_params[id(param)] = param

            if len(all_stochastic_params) > 0:
                self.constraint_to_stochastic_data_map[con] = []
                # no params will appear twice in this iteration
                for param in all_stochastic_params.values():
                    self.stochastic_data_to_constraints_map.\
                        setdefault(param, []).append(con)
                    self.constraint_to_stochastic_data_map[con].\
                        append(param)

            body_variables = tuple(self._collect_variables(con.body).values())
            self.constraint_to_variables_map[con] = []
            for var in body_variables:
                self.variable_to_constraints_map.\
                    setdefault(var, []).append(con)
                self.constraint_to_variables_map[con].append(var)

        # For now, it is okay to have SOSConstraints in the
        # representation of a problem, but the SOS
        # constraints can't have custom weights that
        # represent stochastic data
        for soscon in self.reference_model.component_data_objects(
                SOSConstraint, active=True, descend_into=True):
            for var, weight in soscon.get_items():
                weight_params = tuple(
                    self._collect_mutable_parameters(weight).values())
                if param in self.stochastic_data:
                    raise ValueError(
                        "SOSConstraints with stochastic data are currently"
                        " not supported in embedded stochastic programs. "
                        "The SOSConstraint component '%s' has a weight "
                        "term for variable '%s' that references stochastic"
                        " parameter '%s'" %
                        (soscon.name, var.name, param.name))
                self.variable_to_constraints_map.\
                    setdefault(var, []).append(soscon)
                self.constraint_to_variables_map.\
                    setdefault(soscon, []).append(var)

        sto_varbounds = StochasticVariableBoundsAnnotation()
        for var in self.reference_model.component_data_objects(
                Var, descend_into=True):

            lower_params = tuple(
                self._collect_mutable_parameters(var.lb).values())
            upper_params = tuple(
                self._collect_mutable_parameters(var.ub).values())

            if (len(lower_params) > 0) or \
               (len(upper_params) > 0):
                sto_varbounds.declare(var,
                                      lb=bool(len(lower_params) > 0),
                                      ub=bool(len(upper_params) > 0))

            self.variable_to_stochastic_data_lb_map[var] = []
            for param in lower_params:
                if param in self.stochastic_data:
                    self.stochastic_data_to_variables_lb_map.\
                        setdefault(param, []).append(var)
                    self.variable_to_stochastic_data_lb_map[var].\
                        append(param)
            if len(self.variable_to_stochastic_data_lb_map[var]) == 0:
                del self.variable_to_stochastic_data_lb_map[var]

            self.variable_to_stochastic_data_ub_map[var] = []
            for param in upper_params:
                if param in self.stochastic_data:
                    self.stochastic_data_to_variables_ub_map.\
                        setdefault(param, []).append(var)
                    self.variable_to_stochastic_data_ub_map[var].\
                        append(param)
            if len(self.variable_to_stochastic_data_ub_map[var]) == 0:
                del self.variable_to_stochastic_data_ub_map[var]

        #
        # Generate the explicit annotations
        #

        # first make sure these annotations do not already exist
        if len(
                locate_annotations(self.reference_model,
                                   StochasticConstraintBoundsAnnotation)) > 0:
            raise ValueError(
                "Reference model can not contain "
                "a StochasticConstraintBoundsAnnotation declaration.")
        if len(
                locate_annotations(self.reference_model,
                                   StochasticConstraintBodyAnnotation)) > 0:
            raise ValueError(
                "Reference model can not contain "
                "a StochasticConstraintBodyAnnotation declaration.")
        if len(
                locate_annotations(self.reference_model,
                                   StochasticObjectiveAnnotation)) > 0:
            raise ValueError("Reference model can not contain "
                             "a StochasticObjectiveAnnotation declaration.")

        # now add any necessary annotations
        if sto_obj.has_declarations:
            assert not hasattr(
                self.reference_model,
                ".pyspembeddedsp_stochastic_objective_annotation")
            setattr(self.reference_model,
                    ".pyspembeddedsp_stochastic_objective_annotation", sto_obj)
        if sto_conbody.has_declarations:
            assert not hasattr(
                self.reference_model,
                ".pyspembeddedsp_stochastic_constraint_body_annotation")
            setattr(self.reference_model,
                    ".pyspembeddedsp_stochastic_constraint_body_annotation",
                    sto_conbody)
        if sto_conbounds.has_declarations:
            assert not hasattr(
                self.reference_model,
                ".pyspembeddedsp_stochastic_constraint_bounds_annotation")
            setattr(self.reference_model,
                    ".pyspembeddedsp_stochastic_constraint_bounds_annotation",
                    sto_conbounds)
        if sto_varbounds.has_declarations:
            assert not hasattr(
                self.reference_model,
                ".pyspembeddedsp_stochastic_variable_bounds_annotation")
            setattr(self.reference_model,
                    ".pyspembeddedsp_stochastic_variable_bounds_annotation",
                    sto_varbounds)
예제 #6
0
파일: embeddedsp.py 프로젝트: Pyomo/pyomo
    def __init__(self, reference_model):

        self.reference_model = None
        self.objective = None
        self.time_stages = None

        self.stage_to_variables_map = {}
        self.variable_to_stage_map = {}

        # the set of stochastic data objects
        # (possibly mapped to some distribution)
        self.stochastic_data = None

        # maps between variables and objectives
        self.variable_to_objectives_map = ComponentMap()
        self.objective_to_variables_map = ComponentMap()

        # maps between variables and constraints
        self.variable_to_constraints_map = ComponentMap()
        self.constraint_to_variables_map = ComponentMap()

        # maps between stochastic data and objectives
        self.stochastic_data_to_objectives_map = ComponentMap()
        self.objective_to_stochastic_data_map = ComponentMap()

        # maps between stochastic data and constraints
        self.stochastic_data_to_constraints_map = ComponentMap()
        self.constraint_to_stochastic_data_map = ComponentMap()

        # maps between stochastic data and variable lower and upper bounds
        self.stochastic_data_to_variables_lb_map = ComponentMap()
        self.variable_to_stochastic_data_lb_map = ComponentMap()

        self.stochastic_data_to_variables_ub_map = ComponentMap()
        self.variable_to_stochastic_data_ub_map = ComponentMap()

        self.variable_symbols = ComponentMap()

        if not isinstance(reference_model, Block):
            raise TypeError("reference model input must be a Pyomo model")
        self.reference_model = reference_model

        #
        # Extract stochastic parameters from the
        # StochasticDataAnnotation object
        #
        self.stochastic_data = \
            _extract_stochastic_data(self.reference_model)

        #
        # Get the variable stages from the
        # VariableStageAnnotation object
        #
        (self.stage_to_variables_map,
         self.variable_to_stage_map,
         self._variable_stage_assignments) = \
            _map_variable_stages(self.reference_model)
        self.time_stages = tuple(sorted(self.stage_to_variables_map))
        assert self.time_stages[0] == 1
        self.variable_symbols = generate_cuid_names(self.reference_model,
                                                    ctype=Var)
        # remove the parent blocks from this map
        keys_to_delete = []
        for var in self.variable_symbols:
            if var.parent_component().type() is not Var:
                keys_to_delete.append(var)
        for key in keys_to_delete:
            del self.variable_symbols[key]

        #
        # Get the stage cost components from the StageCostAnnotation
        # and generate a dummy single-scenario scenario tree
        #
        stage_cost_annotation = locate_annotations(
            self.reference_model,
            StageCostAnnotation,
            max_allowed=1)
        if len(stage_cost_annotation) == 0:
            raise ValueError(
                "Reference model is missing stage cost "
                "annotation: %s" % (StageCostAnnotation.__name__))
        else:
            assert len(stage_cost_annotation) == 1
            stage_cost_annotation = stage_cost_annotation[0][1]
        stage_cost_assignments = ComponentMap(
            stage_cost_annotation.expand_entries())

        stage1_cost = None
        stage2_cost = None
        for cdata, stagenum in stage_cost_assignments.items():
            if stagenum == 1:
                stage1_cost = cdata
            elif stagenum == 2:
                stage2_cost = cdata
        if stage1_cost is None:
            raise ValueError("Missing stage cost annotation "
                             "for time stage: 1")
        if stage2_cost is None:
            raise ValueError("Missing stage cost annotation "
                             "for time stage: 2")
        assert stage1_cost is not stage2_cost
        self._stage1_cost = stage1_cost
        self._stage2_cost = stage2_cost

        #
        # Extract the locations of variables and stochastic data
        # within the model
        #
        sto_obj = StochasticObjectiveAnnotation()
        for objcntr, obj in enumerate(
                  self.reference_model.component_data_objects(
                Objective,
                active=True,
                descend_into=True), 1):

            if objcntr > 1:
                raise ValueError(
                    "Reference model can not contain more than one "
                    "active objective")

            self.objective = obj
            self.objective_sense = obj.sense

            obj_params = tuple(
                self._collect_mutable_parameters(obj.expr).values())
            self.objective_to_stochastic_data_map[obj] = []
            for paramdata in obj_params:
                if paramdata in self.stochastic_data:
                    self.stochastic_data_to_objectives_map.\
                        setdefault(paramdata, []).append(obj)
                    self.objective_to_stochastic_data_map[obj].\
                        append(paramdata)
            if len(self.objective_to_stochastic_data_map[obj]) == 0:
                del self.objective_to_stochastic_data_map[obj]
            else:
                # TODO: Can we make this declaration sparse
                #       by identifying which variables have
                #       stochastic coefficients? How to handle
                #       non-linear expressions?
                sto_obj.declare(obj)

            obj_variables = tuple(
                self._collect_variables(obj.expr).values())
            self.objective_to_variables_map[obj] = []
            for var in obj_variables:
                self.variable_to_objectives_map.\
                    setdefault(var, []).append(obj)
                self.objective_to_variables_map[obj].append(var)
            if len(self.objective_to_variables_map[obj]) == 0:
                del self.objective_to_variables_map[obj]

        sto_conbounds = StochasticConstraintBoundsAnnotation()
        sto_conbody = StochasticConstraintBodyAnnotation()
        for con in self.reference_model.component_data_objects(
                Constraint,
                active=True,
                descend_into=True):

            lower_params = tuple(
                self._collect_mutable_parameters(con.lower).values())
            body_params = tuple(
                self._collect_mutable_parameters(con.body).values())
            upper_params = tuple(
                self._collect_mutable_parameters(con.upper).values())

            # TODO: Can we make this declaration sparse
            #       by idenfifying which variables have
            #       stochastic coefficients? How to handle
            #       non-linear expressions? Currently, this
            #       code also fails to detect that mutable
            #       "constant" expressions might fall out
            #       of the body and into the bounds.
            if len(body_params):
                sto_conbody.declare(con)
            if len(body_params) or \
               len(lower_params) or \
               len(upper_params):
                sto_conbounds.declare(con,
                                      lb=bool(len(lower_params) or len(body_params)),
                                      ub=bool(len(upper_params) or len(body_params)))

            all_stochastic_params = {}
            for param in itertools.chain(lower_params,
                                         body_params,
                                         upper_params):
                if param in self.stochastic_data:
                    all_stochastic_params[id(param)] = param

            if len(all_stochastic_params) > 0:
                self.constraint_to_stochastic_data_map[con] = []
                # no params will appear twice in this iteration
                for param in all_stochastic_params.values():
                    self.stochastic_data_to_constraints_map.\
                        setdefault(param, []).append(con)
                    self.constraint_to_stochastic_data_map[con].\
                        append(param)

            body_variables = tuple(
                self._collect_variables(con.body).values())
            self.constraint_to_variables_map[con] = []
            for var in body_variables:
                self.variable_to_constraints_map.\
                    setdefault(var, []).append(con)
                self.constraint_to_variables_map[con].append(var)

        # For now, it is okay to have SOSConstraints in the
        # representation of a problem, but the SOS
        # constraints can't have custom weights that
        # represent stochastic data
        for soscon in self.reference_model.component_data_objects(
                SOSConstraint,
                active=True,
                descend_into=True):
            for var, weight in soscon.get_items():
                weight_params = tuple(
                    self._collect_mutable_parameters(weight).values())
                if param in self.stochastic_data:
                    raise ValueError(
                        "SOSConstraints with stochastic data are currently"
                        " not supported in embedded stochastic programs. "
                        "The SOSConstraint component '%s' has a weight "
                        "term for variable '%s' that references stochastic"
                        " parameter '%s'"
                        % (soscon.name,
                           var.name,
                           param.name))
                self.variable_to_constraints_map.\
                    setdefault(var, []).append(soscon)
                self.constraint_to_variables_map.\
                    setdefault(soscon, []).append(var)

        sto_varbounds = StochasticVariableBoundsAnnotation()
        for var in self.reference_model.component_data_objects(
                Var,
                descend_into=True):

            lower_params = tuple(
                self._collect_mutable_parameters(var.lb).values())
            upper_params = tuple(
                self._collect_mutable_parameters(var.ub).values())

            if (len(lower_params) > 0) or \
               (len(upper_params) > 0):
                sto_varbounds.declare(var,
                                      lb=bool(len(lower_params) > 0),
                                      ub=bool(len(upper_params) > 0))

            self.variable_to_stochastic_data_lb_map[var] = []
            for param in lower_params:
                if param in self.stochastic_data:
                    self.stochastic_data_to_variables_lb_map.\
                        setdefault(param, []).append(var)
                    self.variable_to_stochastic_data_lb_map[var].\
                        append(param)
            if len(self.variable_to_stochastic_data_lb_map[var]) == 0:
                del self.variable_to_stochastic_data_lb_map[var]

            self.variable_to_stochastic_data_ub_map[var] = []
            for param in upper_params:
                if param in self.stochastic_data:
                    self.stochastic_data_to_variables_ub_map.\
                        setdefault(param, []).append(var)
                    self.variable_to_stochastic_data_ub_map[var].\
                        append(param)
            if len(self.variable_to_stochastic_data_ub_map[var]) == 0:
                del self.variable_to_stochastic_data_ub_map[var]

        #
        # Generate the explicit annotations
        #

        # first make sure these annotations do not already exist
        if len(locate_annotations(self.reference_model,
                                  StochasticConstraintBoundsAnnotation)) > 0:
            raise ValueError("Reference model can not contain "
                             "a StochasticConstraintBoundsAnnotation declaration.")
        if len(locate_annotations(self.reference_model,
                                  StochasticConstraintBodyAnnotation)) > 0:
            raise ValueError("Reference model can not contain "
                             "a StochasticConstraintBodyAnnotation declaration.")
        if len(locate_annotations(self.reference_model,
                                  StochasticObjectiveAnnotation)) > 0:
            raise ValueError("Reference model can not contain "
                             "a StochasticObjectiveAnnotation declaration.")

        # now add any necessary annotations
        if sto_obj.has_declarations:
            assert not hasattr(self.reference_model,
                               ".pyspembeddedsp_stochastic_objective_annotation")
            setattr(self.reference_model,
                    ".pyspembeddedsp_stochastic_objective_annotation",
                    sto_obj)
        if sto_conbody.has_declarations:
            assert not hasattr(self.reference_model,
                               ".pyspembeddedsp_stochastic_constraint_body_annotation")
            setattr(self.reference_model,
                    ".pyspembeddedsp_stochastic_constraint_body_annotation",
                    sto_conbody)
        if sto_conbounds.has_declarations:
            assert not hasattr(self.reference_model,
                               ".pyspembeddedsp_stochastic_constraint_bounds_annotation")
            setattr(self.reference_model,
                    ".pyspembeddedsp_stochastic_constraint_bounds_annotation",
                    sto_conbounds)
        if sto_varbounds.has_declarations:
            assert not hasattr(self.reference_model,
                               ".pyspembeddedsp_stochastic_variable_bounds_annotation")
            setattr(self.reference_model,
                    ".pyspembeddedsp_stochastic_variable_bounds_annotation",
                    sto_varbounds)