コード例 #1
0
    def __init__(self, fsfile,
                 fsfct = None,
                 tree_model = None,
                 phopts = None):
        """Initialize a StochSolver object.
        """
        if fsfct is None:
            # Changed in October 2018: None implies AbstractModel
            args_list = _optiondict_2_list(phopts)
            parser = construct_ph_options_parser("")
            options = parser.parse_args(args_list)

            scenario_instance_factory = \
                ScenarioTreeInstanceFactory(fsfile, tree_model)

            try:
                self.scenario_tree = \
                    GenerateScenarioTreeForPH(options,
                                                     scenario_instance_factory)
            except:
                print ("ERROR in StochSolver called from",inspect.stack()[1][3])
                raise RuntimeError("fsfct is None, so assuming",
                      "AbstractModel but could not find all ingredients.")

        else:  # concrete model
            if  callable(fsfct):
                scen_function = fsfct
            else: # better be a string
                fsfile = fsfile.replace('.py','')  # import does not like .py
                # __import__ only gives the top level module
                # probably need to be dealing with modules installed via setup.py
                m = __import__(fsfile)
                for n in fsfile.split(".")[1:]:
                    m = getattr(m, n)
                scen_function = getattr(m, fsfct)

            if tree_model is None:
                treecbname = "pysp_scenario_tree_model_callback"
                tree_maker = getattr(m, treecbname)

                tree = tree_maker()

                scenario_instance_factory = ScenarioTreeInstanceFactory(scen_function, tree_model)

            else:
                # DLW March 21: still not correct
                scenario_instance_factory = \
                    ScenarioTreeInstanceFactory(scen_function, tree_model)


            kwargs = _kwfromphopts(phopts)
            self.scenario_tree = \
                scenario_instance_factory.generate_scenario_tree(**kwargs) #verbose = True)
            instances = scenario_instance_factory. \
                        construct_instances_for_scenario_tree(self.scenario_tree)
            self.scenario_tree.linkInInstances(instances)
コード例 #2
0
def run(args=None):
    ##########################================================#########
    # to import plugins
    import pyomo.environ
    import pysp.pyro.smanager_pyro
    import pysp.plugins.phpyro

    def partialLagrangeParametric(args=None):
        print("lagrangeParam begins ")
        blanks = "                          "  # used for formatting print statements

        class Object(object):
            pass

        Result = Object()

        # options used
        IndVarName = options.indicator_var_name
        CCStageNum = options.stage_num
        alphaTol = options.alpha_tol
        MaxMorePR = options.MaxMorePR  # option to include up to this many PR points above F^* with all delta fixed
        outputFilePrefix = options.outputFilePrefix

        # We write ScenarioList = name, probability
        #          PRoptimal    = probability, min-cost, [selections]
        #          PRmore       = probability, min-cost, [selections]
        # ================ sorted by probability ========================
        #
        # These can be read to avoid re-computing points

        ph = PHFromScratch(options)
        Result.ph = ph
        rootnode = ph._scenario_tree._stages[0]._tree_nodes[
            0]  # use rootnode to loop over scenarios

        if find_active_objective(ph._scenario_tree._scenarios[0]._instance,
                                 safety_checks=True).is_minimizing():
            print("We are solving a MINIMIZATION problem.\n")
        else:
            print("We are solving a MAXIMIZATION problem.\n")

# initialize
        ScenarioList = []
        lambdaval = 0.
        lagrUtil.Set_ParmValue(ph, options.lambda_parm_name, lambdaval)

        # IMPORTANT: Preprocess the scenario instances
        #            before fixing variables, otherwise they
        #            will be preprocessed out of the expressions
        #            and the output_fixed_variable_bounds option
        #            will have no effect when we update the
        #            fixed variable values (and then assume we
        #            do not need to preprocess again because
        #            of this option).
        ph._preprocess_scenario_instances()

        lagrUtil.FixAllIndicatorVariables(ph, IndVarName, 0)
        for scenario in rootnode._scenarios:
            ScenarioList.append((scenario._name, scenario._probability))

        # sorts from min to max probability
        ScenarioList.sort(key=operator.itemgetter(1))
        with open(outputFilePrefix + 'ScenarioList.csv', 'w') as outFile:
            for scenario in ScenarioList:
                outFile.write(scenario[0] + ", " + str(scenario[1]) + "\n")
        Result.ScenarioList = ScenarioList

        print("lambda= " + str(lambdaval) + " ...run begins " +
              str(len(ScenarioList)) + " scenarios")
        SolStat, zL = lagrUtil.solve_ph_code(ph, options)
        print("\t...ends")
        bL = Compute_ExpectationforVariable(ph, IndVarName, CCStageNum)
        if bL > 0:
            print("** bL = " + str(bL) + "  > 0")
            return Result

        print("Initial cost = " + str(zL) + "  for bL = " + str(bL))

        lagrUtil.FixAllIndicatorVariables(ph, IndVarName, 1)

        print("lambda= " + str(lambdaval) + " ...run begins")
        SolStat, zU = lagrUtil.solve_ph_code(ph, options)
        print("\t...ends")
        bU = Compute_ExpectationforVariable(ph, IndVarName, CCStageNum)
        if bU < 1:
            print("** bU = " + str(bU) + "  < 1")

        lagrUtil.FreeAllIndicatorVariables(ph, IndVarName)

        Result.lbz = [[0, bL, zL], [None, bU, zU]]
        Result.selections = [[], ScenarioList]
        NumIntervals = 1
        print("initial gap = " + str(1 - zL / zU) + " \n")
        print("End of test; this is only a test.")

        return Result
################################
# LagrangeParametric ends here
################################

#### start run ####

    AllInOne = False

    ##########################
    # options defined here
    ##########################
    try:
        conf_options_parser = construct_ph_options_parser("lagrange [options]")
        conf_options_parser.add_argument(
            "--alpha",
            help="The alpha level for the chance constraint. Default is 0.05",
            action="store",
            dest="alpha",
            type=float,
            default=0.05)
        conf_options_parser.add_argument(
            "--alpha-min",
            help=
            "The min alpha level for the chance constraint. Default is None",
            action="store",
            dest="alpha_min",
            type=float,
            default=None)
        conf_options_parser.add_argument(
            "--alpha-max",
            help="The alpha level for the chance constraint. Default is None",
            action="store",
            dest="alpha_max",
            type=float,
            default=None)
        conf_options_parser.add_argument(
            "--min-prob",
            help="Tolerance for testing probability > 0. Default is 1e-5",
            action="store",
            dest="min_prob",
            type=float,
            default=1e-5)
        conf_options_parser.add_argument(
            "--alpha-tol",
            help="Tolerance for testing equality to alpha. Default is 1e-5",
            action="store",
            dest="alpha_tol",
            type=float,
            default=1e-5)
        conf_options_parser.add_argument(
            "--MaxMorePR",
            help=
            "Generate up to this many additional PR points after response function. Default is 0",
            action="store",
            dest="MaxMorePR",
            type=int,
            default=0)
        conf_options_parser.add_argument(
            "--outputFilePrefix",
            help="Output file name.  Default is ''",
            action="store",
            dest="outputFilePrefix",
            type=str,
            default="")
        conf_options_parser.add_argument(
            "--stage-num",
            help=
            "The stage number of the CC indicator variable (number, not name). Default is 2",
            action="store",
            dest="stage_num",
            type=int,
            default=2)
        conf_options_parser.add_argument(
            "--lambda-parm-name",
            help=
            "The name of the lambda parameter in the model. Default is lambdaMult",
            action="store",
            dest="lambda_parm_name",
            type=str,
            default="lambdaMult")
        conf_options_parser.add_argument(
            "--indicator-var-name",
            help=
            "The name of the indicator variable for the chance constraint. The default is delta",
            action="store",
            dest="indicator_var_name",
            type=str,
            default="delta")
        conf_options_parser.add_argument(
            "--use-Loane-cuts",
            help="Add the Loane cuts if there is a gap. Default is False",
            action="store_true",
            dest="add_Loane_cuts",
            default=False)
        conf_options_parser.add_argument(
            "--fofx-var-name",
            help=
            "(Loane) The name of the model's auxiliary variable that is constrained to be f(x). Default is fofox",
            action="store",
            dest="fofx_var_name",
            type=str,
            default="fofx")
        conf_options_parser.add_argument(
            "--solve-with-ph",
            help=
            "Perform solves via PH rather than an EF solve. Default is False",
            action="store_true",
            dest="solve_with_ph",
            default=False)
        conf_options_parser.add_argument(
            "--skip-graph",
            help=
            "Do not show the graph at the end. Default is False (i.e. show the graph)",
            action="store_true",
            dest="skip_graph",
            default=False)
        conf_options_parser.add_argument(
            "--write-xls",
            help="Write results into a xls file. Default is False",
            action="store_true",
            dest="write_xls",
            default=False)
        conf_options_parser.add_argument(
            "--skip-ExpFlip",
            help=
            "Do not show the results for flipping the indicator variable for each scenario. Default is False (i.e. show the flipping-results)",
            action="store_true",
            dest="skip_ExpFlip",
            default=False)
        conf_options_parser.add_argument(
            "--HeurFlip",
            help=
            "The number of solutions to evaluate after the heuristic. Default is 3. For 0 the heuristic flip gets skipped.",
            action="store",
            type=int,
            dest="HeurFlip",
            default=3)
        conf_options_parser.add_argument(
            "--HeurMIP",
            help=
            "The mipgap for the scenariowise solves in the heuristic. Default is 0.0001",
            action="store",
            type=float,
            dest="HeurMIP",
            default=0.0001)
        conf_options_parser.add_argument(
            "--interactive",
            help="Enable interactive version of the code. Default is False.",
            action="store_true",
            dest="interactive",
            default=False)
        conf_options_parser.add_argument(
            "--Lgap",
            help=
            "The (relative) Lagrangian gap acceptable for the chance constraint. Default is 10^-4",
            action="store",
            type=float,
            dest="LagrangeGap",
            default=0.0001)
        conf_options_parser.add_argument(
            "--lagrange-method",
            help="The Lagrange multiplier search method",
            action="store",
            dest="lagrange_search_method",
            type=str,
            default="tangential")
        conf_options_parser.add_argument(
            "--max-lambda",
            help="The max value of the multiplier. Default=10^10",
            action="store",
            dest="max_lambda",
            type=float,
            default=10**10)
        conf_options_parser.add_argument(
            "--min-lambda",
            help="The min value of the multiplier. Default=0.0",
            action="store",
            dest="min_lambda",
            type=float,
            default=0)
        conf_options_parser.add_argument(
            "--min-probability",
            help="The min value of scenario probability. Default=10^-15",
            action="store",
            dest="min_probability",
            type=float,
            default=10**(-15))

        ################################################################

        options = conf_options_parser.parse_args(args=args)
        # temporary hack
        options._ef_options = conf_options_parser._ef_options
        options._ef_options.import_argparse(options)
    except SystemExit as _exc:
        # the parser throws a system exit if "-h" is specified - catch
        # it to exit gracefully.
        return _exc.code

    # load the reference model and create the scenario tree - no
    # scenario instances yet.
    if options.verbose:
        print("Loading reference model and scenario tree")
    #scenario_instance_factory, full_scenario_tree = load_models(options)
    scenario_instance_factory = \
         ScenarioTreeInstanceFactory(options.model_directory,
                                     options.instance_directory)

    full_scenario_tree = \
             GenerateScenarioTreeForPH(options,
                                       scenario_instance_factory)

    solver_manager = SolverManagerFactory(options.solver_manager_type)
    if solver_manager is None:
        raise ValueError("Failed to create solver manager of "
                         "type=" + options.solver_manager_type +
                         " specified in call to PH constructor")
    if isinstance(solver_manager, pysp.plugins.phpyro.SolverManager_PHPyro):
        raise ValueError("PHPyro can not be used as the solver manager")

    try:

        if (scenario_instance_factory is None) or (full_scenario_tree is None):
            raise RuntimeError(
                "***ERROR: Failed to initialize model and/or the scenario tree data."
            )

        # load_model gets called again, so lets make sure unarchived directories are used
        options.model_directory = scenario_instance_factory._model_filename
        options.instance_directory = scenario_instance_factory._scenario_tree_filename

        scenario_count = len(full_scenario_tree._stages[-1]._tree_nodes)

        # create ph objects for finding the solution. we do this even if
        # we're solving the extensive form

        if options.verbose:
            print(
                "Loading scenario instances and initializing scenario tree for full problem."
            )

########## Here is where multiplier search is called ############
        Result = partialLagrangeParametric()
#####################################################################################

    finally:
        # delete temporary unarchived directories
        scenario_instance_factory.close()

    print("\nreturned from partialLagrangeParametric")
コード例 #3
0
ファイル: lagrangeParam.py プロジェクト: ramoneim/pysp
def run(args=None):
    ###################################

    print("RUNNING - run args=%s" % str(args))

    import pyomo.environ

    def LagrangeParametric(args=None):
        class Object(object):
            pass

        Result = Object()
        Result.status = 'LagrangeParam begins ' + datetime_string(
        ) + '...running new ph'
        ph = None

        blanks = "                          "  # used for formatting print statements
        # options used
        betaMin = options.beta_min
        betaMax = options.beta_max
        betaTol = options.beta_tol
        gapTol = options.Lagrange_gap
        minProb = options.min_prob
        maxIntervals = options.max_intervals
        maxTime = options.max_time
        IndVarName = options.indicator_var_name
        multName = options.lambda_parm_name
        CCStageNum = options.stage_num
        csvPrefix = options.csvPrefix
        verbosity = options.verbosity
        verbosity = 2  # override for debug (= 3 to get super-debug)
        HGdebug = 0  # special debug (not public)
        # local...may become option
        optTol = gapTol
        ####################################################################
        STARTTIME = time.time()

        Result.status = "options set"
        if verbosity > 1:
            print("From LagrangeParametric, status = %s\tSTARTTIME = %s" \
                    % (str(getattr(Result,'status')), str(STARTTIME)))

        ph = PHFromScratch(options)
        Result.ph = ph
        rootnode = ph._scenario_tree._stages[0]._tree_nodes[
            0]  # use rootnode to loop over scenarios
        ReferenceInstance = ph._instances[
            rootnode._scenarios[0]._name]  # arbitrary scenario

        if find_active_objective(ph._scenario_tree._scenarios[0]._instance,
                                 safety_checks=True).is_minimizing():
            sense = 'min'
        else:
            sense = 'max'

        scenario_count = len(full_scenario_tree._stages[-1]._tree_nodes)
        if options.verbosity > 0:
            print("%s %s scenarios" % (str(sense), str(scenario_count)))

        # initialize
        Result.status = 'starting at ' + datetime_string()
        if verbosity > 0:
            print(Result.status)
        ScenarioList = []
        lambdaval = 0.
        lagrUtil.Set_ParmValue(ph, multName, lambdaval)

        # IMPORTANT: Preprocess the scenario instances
        #            before fixing variables, otherwise they
        #            will be preprocessed out of the expressions
        #            and the output_fixed_variable_bounds option
        #            will have no effect when we update the
        #            fixed variable values (and then assume we
        #            do not need to preprocess again because
        #            of this option).
        ph._preprocess_scenario_instances()

        sumprob = 0.
        minprob = 1.
        maxprob = 0.
        # fixed = 0 to get PR point at b=0
        lagrUtil.FixAllIndicatorVariables(ph, IndVarName, 0)
        for scenario in rootnode._scenarios:
            instance = ph._instances[scenario._name]
            sname = scenario._name
            sprob = scenario._probability
            sumprob = sumprob + sprob
            minprob = min(minprob, sprob)
            maxprob = max(maxprob, sprob)
            ScenarioList.append([sname, sprob])

        ScenarioList.sort(
            key=operator.itemgetter(1))  # sorts from min to max probability
        if verbosity > 0:
            print("probabilities sum to %f range: %f to %f" %
                  (sumprob, minprob, maxprob))
        Result.ScenarioList = ScenarioList

        # Write ScenarioList = name, probability in csv file sorted by probability
        outName = csvPrefix + 'ScenarioList.csv'
        print("writing to %s" % outName)
        with open(outName, 'w') as outFile:
            for scenario in ScenarioList:
                outFile.write(scenario[0] + ", " + str(scenario[1]) + '\n')
        Result.ScenarioList = ScenarioList

        addstatus = 'Scenario List written to ' + csvPrefix + 'ScenarioList.csv'
        Result.status = Result.status + '\n' + addstatus
        if verbosity > 0:
            print(addstatus)

        if verbosity > 0:
            print("solve begins %s" % datetime_string())
            print("\t- lambda = %f" % lambdaval)
        SolStat, zL = lagrUtil.solve_ph_code(ph, options)
        if verbosity > 0:
            print("solve ends %s" % datetime_string())
            print("\t- status = %s" % str(SolStat))
            print("\t- zL = %s" % str(zL))

        bL = Compute_ExpectationforVariable(ph, IndVarName, CCStageNum)
        if bL > 0:
            print("** bL = %s > 0 (all %s = 0)" % (str(bL), str(IndVarName)))
            return Result

        if verbosity > 0:
            print("Initial optimal obj = %s for bL = %s" % (str(zL), str(bL)))

        # fixed = 1 to get PR point at b=1
        lagrUtil.FixAllIndicatorVariables(ph, IndVarName, 1)

        if verbosity > 0:
            print("solve begins %s" % datetime_string())
            print("\t- lambda = %s" % str(lambdaval))
        SolStat, zU = lagrUtil.solve_ph_code(ph, options)
        if verbosity > 0:
            print("solve ends %s" % datetime_string())
            print("\t- status = %s" % str(SolStat))
            print("\t- zU = %s" % str(zU))
        if not SolStat[0:2] == 'ok':
            print(str(SolStat[0:3]) + " is not 'ok'")
            addstatus = "** Solution is non-optimal...aborting"
            print(addstatus)
            Result.status = Result.status + "\n" + addstatus
            return Result

        bU = Compute_ExpectationforVariable(ph, IndVarName, CCStageNum)
        if bU < 1. - betaTol and verbosity > 0:
            print("** Warning:  bU = %s  < 1" % str(bU))

### enumerate points in PR space (all but one scenario)
#      Result.lbz = [ [0,bL,zL], [None,bU,zU] ]
#      for scenario in rootnode._scenarios:
#         sname = scenario._name
#         instance = ph._instances[sname]
#         print "excluding scenario",sname
#         getattr(instance,IndVarName).value = 0
#         print sname,"value =",getattr(instance,IndVarName).value,getattr(instance,IndVarName).fixed
#         SolStat, z = lagrUtil.solve_ph_code(ph, options)
#         b = Compute_ExpectationforVariable(ph, IndVarName, CCStageNum)
#         print "solve ends with status =",SolStat,"(b, z) =",b,z
#         getattr(instance,IndVarName).value = 1
#         Result.lbz.append([None,b,z])
#         for t in instance.TimePeriods:
#           print "Global at",t,"=",instance.posGlobalLoadGenerateMismatch[t].value, \
#                '-',instance.negGlobalLoadGenerateMismatch[t].value,"=",\
#                    instance.GlobalLoadGenerateMismatch[t].value,\
#               "\tDemand =",instance.TotalDemand[t].value, ",",\
#                "Reserve =",instance.ReserveRequirement[t].value
#
#      PrintPRpoints(Result.lbz)
#      return Result
#### end enumeration
########################################################################

        if verbosity > 1:
            print("We have bU = %s ...about to free all %s for %d scenarios" % \
                   (str(bU), str(IndVarName), len(ScenarioList)))

        # free scenario selection variable
        lagrUtil.FreeAllIndicatorVariables(ph, IndVarName)

        if verbosity > 1:
            print("\tall %s freed; elapsed time = %f" %
                  (str(IndVarName), time.time() - STARTTIME))

# initialize with the two endpoints
        Result.lbz = [[0., bL, zL], [None, bU, zU]]
        Result.selections = [[], ScenarioList]
        NumIntervals = 1
        if verbosity > 0:
            print("Initial relative Lagrangian gap = %f maxIntervals = %d" %
                  (1 - zL / zU, maxIntervals))
            if verbosity > 1:
                print("entering while loop %s" % datetime_string())
            print("\n")

############ main loop to search intervals #############
########################################################
        while NumIntervals < maxIntervals:
            lapsedTime = time.time() - STARTTIME
            if lapsedTime > maxTime:
                addstatus = '** max time reached ' + str(lapsedTime)
                print(addstatus)
                Result.status = Result.status + '\n' + addstatus
                break
            if verbosity > 1:
                print("Top of while with %d intervals elapsed time = %f" %
                      (NumIntervals, lapsedTime))
                PrintPRpoints(Result.lbz)

            lambdaval = None
            ### loop over PR points to find first unfathomed interval to search ###
            for PRpoint in range(1, len(Result.lbz)):
                if Result.lbz[PRpoint][0] == None:
                    # multiplier = None means interval with upper endpoint at PRpoint not fathomed
                    bL = Result.lbz[PRpoint - 1][1]
                    zL = Result.lbz[PRpoint - 1][2]
                    bU = Result.lbz[PRpoint][1]
                    zU = Result.lbz[PRpoint][2]
                    lambdaval = (zU - zL) / (bU - bL)
                    break

#############################
# Exited from the for loop
            if verbosity > 1:
                print("exited for loop with PRpoint = %s ...lambdaval = %s" %
                      (PRpoint, lambdaval))
            if lambdaval == None: break  # all intervals are fathomed

            if verbosity > 1: PrintPRpoints(Result.lbz)
            if verbosity > 0:
                print("Searching for b in [%s, %s] with %s = %f" % (str(
                    round(bL, 4)), str(round(bU, 4)), multName, lambdaval))

# search interval (bL,bU)
            lagrUtil.Set_ParmValue(ph, multName, lambdaval)
            if verbosity > 0:
                print("solve begins %s" % datetime_string())
                print("\t- %s = %f" % (multName, lambdaval))

            #########################################################
            SolStat, Lagrangian = lagrUtil.solve_ph_code(ph, options)
            #########################################################
            if not SolStat[0:2] == 'ok':
                addstatus = "** Solution status " + SolStat + " is not optimal"
                print(addstatus)
                Result.status = Result.status + "\n" + addstatus
                return Result

            b = Compute_ExpectationforVariable(ph, IndVarName, CCStageNum)
            z = Lagrangian + lambdaval * b
            if verbosity > 0:
                print("solve ends %s" % datetime_string())
                print("\t- Lagrangian = %f" % Lagrangian)
                print("\t- b = %s" % str(b))
                print("\t- z = %s" % str(z))
                print("\n")

# We have PR point (b,z), which may be new or one of the endpoints
##################################################################

######### Begin tolerance tests ##########
# Test that b is in [bL,bU]
            if verbosity > 1: print("\ttesting b")
            if b < bL - betaTol or b > bU + betaTol:
                addstatus = "** fatal error: probability (= " + str(b) + \
                    ") is outside interval, (" + str(bL) + ", " + str(bU) + ")"
                addstatus = addstatus + "\n\t(tolerance = " + str(
                    betaTol) + ")"
                print(addstatus + '\n')
                Result.status = Result.status + addstatus
                return Result
# Test that z is in [zL,zU]
            if verbosity > 1: print("\ttesting z")
            # using optTol as absolute tolerance (not relative)
            #   ...if we reconsider, need to allow negative z-values
            if z < zL - optTol or z > zU + optTol:
                addstatus = "** fatal error: obj (= " + str(z) + \
                    ") is outside interval, (" + str(zL) + ", " + str(zU) + ")"
                print(addstatus + '\n')
                Result.status = Result.status + addstatus
                return Result

# Ok, we have (b,z) in [(bL,zL), (bU,zU)], at least within tolerances

            oldLagrangian = zL - lambdaval * bL
            # ensure lambdaval set such that endpoints have same Lagrangian value
            # (this is probably unnecessary, but check anyway)
            if abs(oldLagrangian -
                   (zU - lambdaval * bU)) > optTol * abs(oldLagrangian):
                addstatus = "** fatal error: Lagrangian at (bL,zL) = " + \
                    str(oldLagrangian) + " not= " + str(zU-lambdaval*bU) + \
                    "\n\t(optTol = " + str(optTol) + ")"
                Result.status = Result.status + addstatus
                return Result

# no more fatal error tests...need to know if (b,z) is endpoint or new

            if verbosity > 1: print("No anomalies...testing if b = bL or bU")

            # Test if endpoint is an alternative optimum of Lagrangian
            # ...using optTol as *relative* tolerance
            # (could use other reference values -- eg, avg or max of old and new Lagrangian values)
            refValue = max(min(abs(oldLagrangian), abs(Lagrangian)), 1.)
            alternativeOpt = abs(oldLagrangian -
                                 Lagrangian) <= optTol * refValue

            # alternativeOpt = True means we computed point (b,z) is alternative optimum such that:
            #   case 1: (b,z) = endpoint, in which case we simply fathom [bL,bU] by setting PRpoint
            #            to [lambdaval,bU,zU] (the numeric value of multiplier means fathomed)
            #   case 2: (b,z) is new PR point on line segment, in which case we split into
            #           [bL,b] and [b,bU], with both fathomed

            if verbosity > 1:
                print("oldLagrangian = %s" % str(oldLagrangian))
                if alternativeOpt:
                    print(":= Lagrangian = %s" % str(Lagrangian))
                else:
                    print("> Lagrangian = %s" % str(Lagrangian))

            if alternativeOpt:
                # setting multiplier of (bU,zU) to a numeric fathoms the interval [bL,bU]
                Result.lbz[PRpoint][0] = lambdaval

# test if (b,z) is an endpoint
            newPRpoint = abs(b - bL) > betaTol and abs(b - bU) > betaTol
            if not newPRpoint:
                # ...(b,z) is NOT an endpoint (or sufficiently close), so split and fathom
                if verbosity > 1:
                    print("\tnot an endpoint\tlbz = %s" %
                          str(Result.lbz[PRpoint]))
                if verbosity > 0:
                    print("Lagangian solution is new PR point on line segment of (" \
                       + str(bL) + ", " + str(bU) +")")
                    print(
                        "\tsplitting (bL,bU) into (bL,b) and (b,bU), both fathomed"
                    )
# note:  else ==> b = bL or bU, so we do nothing, having already fathomed [bL,bU]

# (b,z) is new PR point, so split interval (still in while loop)
##########################################
# alternative optimum ==> split & fathom: (bL,b), (b,bU)
            if verbosity > 1:
                print("\talternativeOpt %s newPRpoint = %s" %
                      (alternativeOpt, newPRpoint))
            if newPRpoint:
                NumIntervals += 1
                if alternativeOpt:
                    if verbosity > 1:
                        print("\tInsert [lambdaval,b,z] at %f" % PRpoint)
                    Result.lbz = Insert([lambdaval, b, z], PRpoint, Result.lbz)
                    addstatus = "Added PR point on line segment of envelope"
                    if verbosity > 0: print(addstatus + '\n')
                else:
                    if verbosity > 1:
                        print("\tInsert [None,b,z] at %f" % PRpoint)
                    Result.lbz = Insert([None, b, z], PRpoint, Result.lbz)
                    addstatus = "new envelope extreme point added (interval split, not fathomed)"
                Result.status = Result.status + "\n" + addstatus

                if verbosity > 1:
                    print("...after insertion:")
                    PrintPRpoints(Result.lbz)

# get the selections of new point (ie, scenarios for which delta=1)
                Selections = []
                for scenario in ScenarioList:
                    instance = ph._instances[scenario[0]]
                    if getattr(instance, IndVarName).value == 1:
                        Selections.append(scenario)
                Result.selections = Insert(Selections, PRpoint,
                                           Result.selections)

                if verbosity > 0:
                    print("Interval "+str(PRpoint)+", ["+str(bL)+", "+str(bU)+ \
                      "] split at ("+str(b)+", "+str(z)+")")
                    print("\tnew PR point has " + str(len(Selections)) +
                          " selections")

                if verbosity > 1:
                    print("test that selections list aligned with lbz")
                if not len(Result.lbz) == len(Result.selections):
                    print("** fatal error: lbz not= selections")
                    PrintPRpoints(Result.lbz)
                    print("Result.selections:")
                    for i in range(Result.selections):
                        print("%d %f" % (i, Result.selections[i]))
                    return Result

# ok, we have split and/or fathomed interval
            if NumIntervals >= maxIntervals:
                # we are about to leave while loop due to...
                addstatus = "** terminating because number of intervals = " + \
                        str(NumIntervals) + " >= max = " + str(maxIntervals)
                if verbosity > 0: print(addstatus + '\n')
                Result.status = Result.status + "\n" + addstatus

# while loop continues
            if verbosity > 1:
                print("bottom of while loop")
                PrintPRpoints(Result.lbz)

###################################################
# end while NumIntervals < maxIntervals:
#     ^ this is indentation of while loop
################ end while loop ###################

        if verbosity > 1: print("\nend while loop...setting multipliers")
        for i in range(1, len(Result.lbz)):
            db = Result.lbz[i][1] - Result.lbz[i - 1][1]
            dz = Result.lbz[i][2] - Result.lbz[i - 1][2]
            if dz > 0:
                Result.lbz[i][0] = dz / db
            else:
                #print "dz =",dz," at ",i,": ",Result.lbz[i]," -",Result.lbz[i-1]
                Result.lbz[i][0] = 0
        if verbosity > 0: PrintPRpoints(Result.lbz)

        addstatus = '\nLagrange multiplier search ends' + datetime_string()
        if verbosity > 0:
            print(addstatus + '\n')
        Result.status = Result.status + addstatus

        outName = csvPrefix + "PRoptimal.csv"
        with open(outName, 'w') as outFile:
            if verbosity > 0:
                print("writing PR points to " + outName + '\n')
            for lbz in Result.lbz:
                outFile.write(str(lbz[1]) + ", " + str(lbz[2]) + '\n')

        outName = csvPrefix + "OptimalSelections.csv"
        with open(outName, 'w') as outFile:
            if verbosity > 0:
                print("writing optimal selections for each PR point to " +
                      csvPrefix + 'PRoptimal.csv\n')
            for selections in Result.selections:
                char = ""
                thisSelection = ""
                for slist in selections:
                    if slist:
                        thisSelection = thisSelection + char + slist[0]
                        char = ","
                outFile.write(thisSelection + '\n')

        if verbosity > 0:
            print("\nReturning status:\n %s \n=======================" %
                  Result.status)

################################
        if verbosity > 2:
            print("\nAbout to return...Result attributes: %d" %
                  len(inspect.getmembers(Result)))
            for attr in inspect.getmembers(Result):
                print(attr[0])
            print("\n===========================================")
# LagrangeParametric ends here
        return Result
################################

####################################### start run ####################################

    AllInOne = False

    ########################
    # options defined here
    ########################
    try:
        conf_options_parser = construct_ph_options_parser("lagrange [options]")
        conf_options_parser.add_argument(
            "--beta-min",
            help="The min beta level for the chance constraint. Default is 0",
            action="store",
            dest="beta_min",
            type=float,
            default=0.)
        conf_options_parser.add_argument(
            "--beta-max",
            help="The beta level for the chance constraint. Default is 1.",
            action="store",
            dest="beta_max",
            type=float,
            default=1.)
        conf_options_parser.add_argument(
            "--beta-tol",
            help="Tolerance for testing equality to beta. Default is 1e-5",
            action="store",
            dest="beta_tol",
            type=float,
            default=1e-5)
        conf_options_parser.add_argument(
            "--Lagrange-gap",
            help=
            "The (relative) Lagrangian gap acceptable for the chance constraint. Default is 10^-4",
            action="store",
            type=float,
            dest="Lagrange_gap",
            default=0.0001)
        conf_options_parser.add_argument(
            "--min-prob",
            help="Tolerance for testing probability > 0. Default is 1e-9",
            action="store",
            dest="min_prob",
            type=float,
            default=1e-5)
        conf_options_parser.add_argument(
            "--max-intervals",
            help=
            "The max number of intervals generated; if causes termination, non-fathomed intervals have multiplier=None.  Default = 100.",
            action="store",
            dest="max_intervals",
            type=int,
            default=100)
        conf_options_parser.add_argument(
            "--max-time",
            help="Maximum time (seconds). Default is 3600.",
            action="store",
            dest="max_time",
            type=float,
            default=3600)
        conf_options_parser.add_argument(
            "--lambda-parm-name",
            help=
            "The name of the lambda parameter in the model. Default is lambdaMult",
            action="store",
            dest="lambda_parm_name",
            type=str,
            default="lambdaMult")
        conf_options_parser.add_argument(
            "--indicator-var-name",
            help=
            "The name of the indicator variable for the chance constraint. The default is delta",
            action="store",
            dest="indicator_var_name",
            type=str,
            default="delta")
        conf_options_parser.add_argument(
            "--stage-num",
            help=
            "The stage number of the CC indicator variable (number, not name). Default is 2",
            action="store",
            dest="stage_num",
            type=int,
            default=2)
        conf_options_parser.add_argument(
            "--csvPrefix",
            help="Output file name.  Default is ''",
            action="store",
            dest="csvPrefix",
            type=str,
            default='')
        conf_options_parser.add_argument(
            "--verbosity",
            help=
            "verbosity=0 is no extra output, =1 is medium, =2 is debug, =3 super-debug. Default is 1.",
            action="store",
            dest="verbosity",
            type=int,
            default=1)
        # The following needed for solve_ph_code in lagrangeutils
        conf_options_parser.add_argument(
            "--solve-with-ph",
            help=
            "Perform solves via PH rather than an EF solve. Default is False",
            action="store_true",
            dest="solve_with_ph",
            default=False)
        ##HG: deleted params filed as deletedParam.py
        #######################################################################################################

        options = conf_options_parser.parse_args(args=args)
        # temporary hack
        options._ef_options = conf_options_parser._ef_options
        options._ef_options.import_argparse(options)
    except SystemExit as _exc:
        # the parser throws a system exit if "-h" is specified - catch
        # it to exit gracefully.
        return _exc.code

    # create the reference instances and the scenario tree - no
    # scenario instances yet.
    if options.verbosity > 0:
        print("Loading reference model and scenario tree")
# Dec 18
#   scenario_instance_factory, full_scenario_tree = load_models(options)
    scenario_instance_factory = \
         ScenarioTreeInstanceFactory(options.model_directory,
                                     options.instance_directory)

    full_scenario_tree = \
             GenerateScenarioTreeForPH(options,
                                       scenario_instance_factory)

    ####
    try:
        if (scenario_instance_factory is None) or (full_scenario_tree is None):
            raise RuntimeError(
                "***ERROR: Failed to initialize the model and/or scenario tree data."
            )

        # load_model gets called again, so lets make sure unarchived directories are used
        options.model_directory = scenario_instance_factory._model_filename
        options.instance_directory = scenario_instance_factory._scenario_tree_filename

        ########## Here is where multiplier search is called from run() ############
        Result = LagrangeParametric()
#####################################################################################
    finally:

        # delete temporary unarchived directories
        scenario_instance_factory.close()

    if options.verbosity > 0:
        print("\n===========================================")
        print("\nreturned from LagrangeParametric")
        if options.verbosity > 2:
            print("\nFrom run, Result should have status and ph objects...")
            for attr in inspect.getmembers(Result):
                print(attr)
            print("\n===========================================")

    try:
        status = Result.status
        print("status = " + str(Result.status))
    except:
        print("status not defined")
        sys.exit()

    try:
        lbz = Result.lbz
        PrintPRpoints(lbz)
        with open(options.csvPrefix + "PRoptimal.csv", 'w') as outFile:
            for lbz in Result.lbz:
                outFile.write(str(lbz[1]) + ", " + str(lbz[2]) + '\n')
    except:
        print("Result.lbz not defined")
        sys.exit()

    try:
        ScenarioList = Result.ScenarioList
        ScenarioList.sort(key=operator.itemgetter(1))
        with open(options.csvPrefix + "ScenarioList.csv", 'w') as outFile:
            for scenario in ScenarioList:
                outFile.write(scenario[0] + ", " + str(scenario[1]) + '\n')
    except:
        print("Result.ScenarioList not defined")
        sys.exit()
コード例 #4
0
class StochSolver:
    """A class for solving stochastic versions of concrete models and
    abstract models.
    Inspired by the IDAES use case and by daps ability to create tree models.
    Author: David L. Woodruff, February 2017

    Args:
      fsfile (str): is a path to the file that contains the scenario
                    callback for concrete or the reference model for abstract.
      fsfct (str, or fct, or None):
         |  str:   callback function name in the file
         |  fct:   callback function (fsfile is ignored)
         |  None:  it is a AbstractModel
      tree_model (concrete model, or networkx tree, or path):
        gives the tree as a concrete model (which could be a fct)
        or a valid networkx scenario tree
        or path to AMPL data file.
      phopts: dictionary of ph options; needed during construction
              if there is bundling.

    Attributes:
       scenario_tree: scenario tree object (that includes data)

    """
    def __init__(self, fsfile, fsfct=None, tree_model=None, phopts=None):
        """Initialize a StochSolver object.
        """
        if fsfct is None:
            # Changed in October 2018: None implies AbstractModel
            args_list = _optiondict_2_list(phopts)
            parser = construct_ph_options_parser("")
            options = parser.parse_args(args_list)

            scenario_instance_factory = \
                ScenarioTreeInstanceFactory(fsfile, tree_model)

            try:
                self.scenario_tree = \
                    GenerateScenarioTreeForPH(options,
                                                     scenario_instance_factory)
            except:
                print("ERROR in StochSolver called from",
                      inspect.stack()[1][3])
                raise RuntimeError(
                    "fsfct is None, so assuming",
                    "AbstractModel but could not find all ingredients.")

        else:  # concrete model
            if callable(fsfct):
                scen_function = fsfct
            else:  # better be a string
                fsfile = fsfile.replace('.py', '')  # import does not like .py
                # __import__ only gives the top level module
                # probably need to be dealing with modules installed via setup.py
                m = __import__(fsfile)
                for n in fsfile.split(".")[1:]:
                    m = getattr(m, n)
                scen_function = getattr(m, fsfct)

            if tree_model is None:
                treecbname = "pysp_scenario_tree_model_callback"
                tree_maker = getattr(m, treecbname)

                tree = tree_maker()

                scenario_instance_factory = ScenarioTreeInstanceFactory(
                    scen_function, tree_model)

            else:
                # DLW March 21: still not correct
                scenario_instance_factory = \
                    ScenarioTreeInstanceFactory(scen_function, tree_model)

            kwargs = _kwfromphopts(phopts)
            self.scenario_tree = \
                scenario_instance_factory.generate_scenario_tree(**kwargs) #verbose = True)
            instances = scenario_instance_factory. \
                        construct_instances_for_scenario_tree(self.scenario_tree)
            self.scenario_tree.linkInInstances(instances)

    #=========================
    def make_ef(self,
                verbose=False,
                generate_weighted_cvar=False,
                cvar_weight=None,
                risk_alpha=None,
                cc_indicator_var_name=None,
                cc_alpha=0.0):
        """ Make an ef object (used by solve_ef); all Args are optional.

        Args:
            verbose (boolean): indicates verbosity to PySP for construction
            generate_weighted_cvar (boolean): indicates we want weighted CVar
            cvar_weight (float): weight for the cvar term
            risk_alpha (float): alpha value for cvar
            cc_indicator_var_name (string): name of the Var used for chance constraint
            cc_alpha (float): alpha for chance constraint

        Returns:
            ef_instance: the ef object
        """
        return create_ef_instance(
            self.scenario_tree,
            verbose_output=verbose,
            generate_weighted_cvar=generate_weighted_cvar,
            cvar_weight=cvar_weight,
            risk_alpha=risk_alpha,
            cc_indicator_var_name=cc_indicator_var_name,
            cc_alpha=cc_alpha)

    def solve_ef(self,
                 subsolver,
                 sopts=None,
                 tee=False,
                 need_gap=False,
                 verbose=False,
                 generate_weighted_cvar=False,
                 cvar_weight=None,
                 risk_alpha=None,
                 cc_indicator_var_name=None,
                 cc_alpha=0.0):
        """Solve the stochastic program directly using the extensive form.
        All Args other than subsolver are optional.

        Args:
            subsolver (str): the solver to call (e.g., 'ipopt')
            sopts (dict):  solver options
            tee (bool): indicates dynamic solver output to terminal.
            need_gap (bool): indicates the need for the optimality gap
            verbose (boolean): indicates verbosity to PySP for construction
            generate_weighted_cvar (boolean): indicates we want weighted CVar
            cvar_weight (float): weight for the cvar term
            risk_alpha (float): alpha value for cvar
            cc_indicator_var_name (string): name of the Var used for chance constraint
            cc_alpha (float): alpha for chance constraint

        Returns: (`Pyomo solver result`, `float`)

                solve_result is the solver return value.

                absgap is the absolute optimality gap (might not be valid); only if requested

        Note:
           Also update the scenario tree, populated with the solution.
           Also attach the full ef instance to the object. So you might want
           obj = pyo.value(stsolver.ef_instance.MASTER)
           This needs more work to deal with solver failure (dlw, March, 2018)

        """

        self.ef_instance = self.make_ef(
            verbose=verbose,
            generate_weighted_cvar=generate_weighted_cvar,
            cvar_weight=cvar_weight,
            risk_alpha=risk_alpha,
            cc_indicator_var_name=cc_indicator_var_name,
            cc_alpha=cc_alpha)

        solver = SolverFactory(subsolver)
        if sopts is not None:
            for key in sopts:
                solver.options[key] = sopts[key]

        if need_gap:
            solve_result = solver.solve(self.ef_instance,
                                        tee=tee,
                                        load_solutions=False)
            if len(solve_result.solution) > 0:
                absgap = solve_result.solution(0).gap
            else:
                absgap = None
            self.ef_instance.solutions.load_from(solve_result)
        else:
            solve_result = solver.solve(self.ef_instance, tee=tee)

        # note: the objective is probably called MASTER
        #print ("debug value(ef_instance.MASTER)=",value(ef_instance.MASTER))
        self.scenario_tree.pullScenarioSolutionsFromInstances()
        self.scenario_tree.snapshotSolutionFromScenarios()  # update nodes
        if need_gap:
            return solve_result, absgap
        else:
            return solve_result

    #=========================
    def solve_ph(self, subsolver, default_rho, phopts=None, sopts=None):
        """Solve the stochastic program given by this.scenario_tree using ph

        Args:
            subsolver (str): the solver to call (e.g., 'ipopt')
            default_rho (float): the rho value to use by default
            phopts: dictionary of ph options (optional)
            sopts: dictionary of subsolver options (optional)

        Returns: the ph object

        Note:
            Updates the scenario tree, populated with the xbar values;
            however, you probably want to do
            obj, xhat = ph.compute_and_report_inner_bound_using_xhat()
            where ph is the return value.

        """

        ph = None

        # Build up the options for PH.
        parser = construct_ph_options_parser("")
        phargslist = ['--default-rho', str(default_rho)]
        phargslist.append('--solver')
        phargslist.append(str(subsolver))
        phargslist = _optiondict_2_list(phopts, args_list=phargslist)

        # Subproblem options go to PH as space-delimited, equals-separated pairs.
        if sopts is not None:
            soptstring = ""
            for key in sopts:
                soptstring += key + '=' + str(sopts[key]) + ' '
            phargslist.append('--scenario-solver-options')
            phargslist.append(soptstring)
        phoptions = parser.parse_args(phargslist)

        # construct the PH solver object
        try:
            ph = PHAlgorithmBuilder(phoptions, self.scenario_tree)
        except:
            print("Internal error: ph construction failed.")
            if ph is not None:
                ph.release_components()
            raise

        retval = ph.solve()
        if retval is not None:
            raise RuntimeError("ph Failure Encountered=" + str(retval))
        # dlw May 2017: I am not sure if the next line is really needed
        ph.save_solution()

        return ph

    #=========================
    def root_Var_solution(self):
        """Generator to loop over x-bar

        Yields:
            name, value pair for root node solution values
        """
        root_node = self.scenario_tree.findRootNode()
        for variable_id in sorted(root_node._variable_ids):
            var_name, index = root_node._variable_ids[variable_id]
            name = var_name
            if index is not None:
                name += _name_index_generator(index)
            yield name, root_node._solution[variable_id]

    #=========================
    def root_E_obj(self):
        """post solve Expected cost of the solution in the scenario tree (xbar)

        Returns:
            float: the expected costs of the solution in the tree (xbar)
        """
        root_node = self.scenario_tree.findRootNode()
        return root_node.computeExpectedNodeCost()
コード例 #5
0
ファイル: lagrangeMorePR.py プロジェクト: ramoneim/pysp
def run(args=None):
    ###################################

    # to import plugins
    import pyomo.environ
    import pysp.plugins.phpyro

    def LagrangeMorePR(args=None):
        print("lagrangeMorePR begins %s" % datetime_string())
        blanks = "                          "  # used for formatting print statements

        class Object(object):
            pass

        Result = Object()

        # options used
        betaTol = options.beta_tol  # tolerance used to separate b-values
        IndVarName = options.indicator_var_name
        multName = options.lambda_parm_name
        CCStageNum = options.stage_num
        MaxMorePR = options.max_number  # max PR points to be generated (above F^* with all delta fixed)
        MaxTime = options.max_time  # max time before terminate
        csvPrefix = options.csvPrefix  # input filename prefix (eg, case name)
        probFileName = options.probFileName  # name of file containing probabilities
        ##HG override
        #      options.verbosity = 2
        verbosity = options.verbosity

        Result.status = 'starting ' + datetime_string()
        STARTTIME = time.time()

        ph = PHFromScratch(options)
        rootnode = ph._scenario_tree._stages[0]._tree_nodes[
            0]  # use rootnode to loop over scenarios

        if find_active_objective(ph._scenario_tree._scenarios[0]._instance,
                                 safety_checks=True).is_minimizing():
            print("We are solving a MINIMIZATION problem.")
        else:
            print("We are solving a MAXIMIZATION problem.")

# initialize
        ScenarioList = []
        with open(csvPrefix + "ScenarioList.csv", 'r') as inputFile:
            for line in inputFile.readlines():
                L = line.split(',')
                ScenarioList.append([L[0], float(L[1])])

        addstatus = str(
            len(ScenarioList)
        ) + ' scenarios read from file: ' + csvPrefix + 'ScenarioList.csv'
        if verbosity > 0: print(addstatus)
        Result.status = Result.status + '\n' + addstatus

        PRoptimal = []
        with open(csvPrefix + "PRoptimal.csv", 'r') as inputFile:
            for line in inputFile.readlines():
                bzS = line.split(',')
                PRoptimal.append([None, float(bzS[0]), float(bzS[1])])

        addstatus = str(
            len(PRoptimal)
        ) + ' PR points read from file: ' + csvPrefix + 'PRoptimal.csv (envelope function)'
        if verbosity > 0:
            print(addstatus)
        Result.status = Result.status + '\n' + addstatus
        # ensure PR points on envelope function are sorted by probability
        PRoptimal.sort(key=operator.itemgetter(1))

        PRoptimal[0][0] = 0  # initial lambda (for b=0)
        for p in range(1, len(PRoptimal)):
            dz = PRoptimal[p][2] - PRoptimal[p - 1][2]
            db = PRoptimal[p][1] - PRoptimal[p - 1][1]
            PRoptimal[p][0] = dz / db
        if verbosity > 0:
            PrintPRpoints(PRoptimal)
        Result.PRoptimal = PRoptimal

        lambdaval = 0.
        lagrUtil.Set_ParmValue(ph, options.lambda_parm_name, lambdaval)

        # IMPORTANT: Preprocess the scenario instances
        #            before fixing variables, otherwise they
        #            will be preprocessed out of the expressions
        #            and the output_fixed_variable_bounds option
        #            will have no effect when we update the
        #            fixed variable values (and then assume we
        #            do not need to preprocess again because
        #            of this option).
        ph._preprocess_scenario_instances()

        ## read scenarios to select for each PR point on envelope function
        with open(csvPrefix + "OptimalSelections.csv", 'r') as inputFile:
            OptimalSelections = []
            for line in inputFile.readlines():
                if len(line) == 0: break  # eof
                selections = line.split(',')
                L = len(selections)
                Ls = len(selections[L - 1])
                selections[L - 1] = selections[L - 1][0:Ls - 1]
                if verbosity > 1:
                    print(str(selections))
                OptimalSelections.append(selections)

        Result.OptimalSelections = OptimalSelections

        addstatus = str(len(OptimalSelections)) + ' Optimal selections read from file: ' \
              + csvPrefix + 'OptimalSelections.csv'
        Result.status = Result.status + '\n' + addstatus

        if len(OptimalSelections) == len(PRoptimal):
            if verbosity > 0:
                print(addstatus)
        else:
            addstatus = addstatus + '\n** Number of selections not equal to number of PR points'
            print(addstatus)
            Result.status = Result.status + '\n' + addstatus
            print(str(OptimalSelections))
            print((PRoptimal))
            return Result

#####################################################################################

# get probabilities
        if probFileName is None:
            # ...generate from widest gap regions
            PRlist = FindPRpoints(options, PRoptimal)
        else:
            # ...read probabilities
            probList = []
            with open(probFileName, 'r') as inputFile:
                if verbosity > 0:
                    print("reading from probList = " + probFileName)
                for line in inputFile.readlines():  # 1 probability per line
                    if len(line) == 0:
                        break
                    prob = float(line)
                    probList.append(prob)

            if verbosity > 0:
                print("\t " + str(len(probList)) + " probabilities")
            if verbosity > 1:
                print(str(probList))
            PRlist = GetPoints(options, PRoptimal, probList)
            if verbosity > 1:
                print("PRlist:")
                for interval in PRlist:
                    print(str(interval))

# We now have PRlist = [[i, b], ...], where b is in PRoptimal interval (i-1,i)
        addstatus = str(len(PRlist)) + ' probabilities'
        if verbosity > 0:
            print(addstatus)
        Result.status = Result.status + '\n' + addstatus

        #####################################################################################

        lapsedTime = time.time() - STARTTIME
        addstatus = 'Initialize complete...lapsed time = ' + str(lapsedTime)
        if verbosity > 1:
            print(addstatus)
        Result.status = Result.status + '\n' + addstatus

        #####################################################################################

        if verbosity > 1:
            print(
                "\nlooping over Intervals to generate PR points by flipping heuristic"
            )
        Result.morePR = []
        for interval in PRlist:
            lapsedTime = time.time() - STARTTIME
            if lapsedTime > MaxTime:
                addstatus = '** lapsed time = ' + str(
                    lapsedTime) + ' > max time = ' + str(MaxTime)
                if verbosity > 0: print(addstatus)
                Result.status = Result.status + '\n' + addstatus
                break

            i = interval[0]  # = PR point index
            b = interval[
                1]  # = target probability to reach by flipping from upper endpoint
            bU = PRoptimal[i][1]  # = upper endpoint
            bL = PRoptimal[i - 1][1]  # = lower endpoint
            if verbosity > 1:
                print( "target probability = "+str(b)+" < bU = PRoptimal[" + str(i) + "][1]" \
                     " and > bL = PRoptimal["+str(i-1)+"][1]")
            if b < bL or b > bU:
                addstatus = '** probability = '+str(b) + ', not in gap interval: (' \
                    + str(bL) + ', ' + str(bU) + ')'
                print(addstatus)
                print(str(PRoptimal))
                print(str(PRlist))
                Result.status = Result.status + '\n' + addstatus
                return Result

            if verbosity > 1:
                print( "i = "+str(i)+" : Starting with bU = "+str(bU)+" having "+ \
                    str(len(OptimalSelections[i]))+ " selections:")
                print(str(OptimalSelections[i]))

# first fix all scenarios = 0
            for sname, sprob in ScenarioList:
                scenario = ph._scenario_tree.get_scenario(sname)
                lagrUtil.FixIndicatorVariableOneScenario(
                    ph, scenario, IndVarName, 0)

# now fix optimal selections = 1
            for sname in OptimalSelections[i]:
                scenario = ph._scenario_tree.get_scenario(sname)
                lagrUtil.FixIndicatorVariableOneScenario(
                    ph, scenario, IndVarName, 1)

# flip scenario selections from bU until we reach b (target probability)
            bNew = bU
            for sname, sprob in ScenarioList:
                scenario = ph._scenario_tree.get_scenario(sname)
                if bNew - sprob < b:
                    continue
                instance = ph._instances[sname]
                if getattr(instance, IndVarName).value == 0:
                    continue
                bNew = bNew - sprob
                # flipped scenario selection
                lagrUtil.FixIndicatorVariableOneScenario(
                    ph, scenario, IndVarName, 0)
                if verbosity > 1:
                    print("\tflipped " + sname + " with prob = " + str(sprob) +
                          " ...bNew = " + str(bNew))

            if verbosity > 1:
                print("\tflipped selections reach " + str(bNew) +
                      " >= target = " + str(b) + " (bL = " + str(bL) + ")")
            if bNew <= bL + betaTol or bNew >= bU - betaTol:
                if verbosity > 0:
                    print(
                        "\tNot generating PR point...flipping from bU failed")
                continue  # to next interval in list

# ready to solve to get cost for fixed scenario selections associated with probability = bNew

            if verbosity > 1:
                # check that scenarios are fixed as they should be
                totalprob = 0.
                for scenario in ScenarioList:
                    sname = scenario[0]
                    sprob = scenario[1]
                    instance = ph._instances[sname]
                    print("fix "+sname+" = "+str(getattr(instance,IndVarName).value)+\
                       " is "+str(getattr(instance,IndVarName).fixed)+" probability = "+str(sprob))
                    if getattr(instance, IndVarName).value == 1:
                        totalprob = totalprob + sprob
                    lambdaval = getattr(instance, multName).value
                print("\ttotal probability = %f" % totalprob)

# solve (all delta fixed); lambda=0, so z = Lagrangian
            if verbosity > 0:
                print("solve begins %s" % datetime_string())
                print("\t- lambda = %f" % lambdaval)
            SolStat, z = lagrUtil.solve_ph_code(ph, options)
            b = Compute_ExpectationforVariable(ph, IndVarName, CCStageNum)
            if verbosity > 0:
                print("solve ends %s" % datetime_string())
                print("\t- SolStat = %s" % str(SolStat))
                print("\t- b = %s" % str(b))
                print("\t- z = %s" % str(z))
                print("(adding to more PR points)")

            Result.morePR.append([None, b, z])
            if verbosity > 1:
                PrintPRpoints(Result.morePR)
        ######################################################
        # end loop over target probabilities

        with open(csvPrefix + "PRmore.csv", 'w') as outFile:
            for point in Result.morePR:
                outFile.write(str(point[1]) + ',' + str(point[2]))

        addstatus = str(
            len(Result.morePR
                )) + ' PR points written to file: ' + csvPrefix + 'PRmore.csv'
        if verbosity > 0: print(addstatus)
        Result.status = Result.status + '\n' + addstatus
        addstatus = 'lapsed time = ' + putcommas(time.time() - STARTTIME)
        if verbosity > 0: print(addstatus)
        Result.status = Result.status + '\n' + addstatus

        return Result
################################
# LagrangeMorePR ends here
################################

#### start run ####

    AllInOne = False
    #   VERYSTARTTIME=time.time()
    #   print "##############VERYSTARTTIME:",str(VERYSTARTTIME-VERYSTARTTIME)

    ##########################
    # options defined here
    ##########################
    try:
        conf_options_parser = construct_ph_options_parser("lagrange [options]")
        conf_options_parser.add_argument(
            "--beta-min",
            help=
            "The min beta level for the chance constraint. Default is None",
            action="store",
            dest="beta_min",
            type=float,
            default=None)
        conf_options_parser.add_argument(
            "--beta-max",
            help="The beta level for the chance constraint. Default is None",
            action="store",
            dest="beta_max",
            type=float,
            default=None)
        conf_options_parser.add_argument(
            "--min-prob",
            help="Tolerance for testing probability > 0. Default is 1e-5",
            action="store",
            dest="min_prob",
            type=float,
            default=1e-5)
        conf_options_parser.add_argument(
            "--beta-tol",
            help="Tolerance for testing equality to beta. Default is 10^-2",
            action="store",
            dest="beta_tol",
            type=float,
            default=1e-2)
        conf_options_parser.add_argument(
            "--Lagrange-gap",
            help=
            "The (relative) Lagrangian gap acceptable for the chance constraint. Default is 10^-4.",
            action="store",
            type=float,
            dest="Lagrange_gap",
            default=0.0001)
        conf_options_parser.add_argument(
            "--max-number",
            help="The max number of PR points. Default = 10.",
            action="store",
            dest="max_number",
            type=int,
            default=10)
        conf_options_parser.add_argument(
            "--max-time",
            help="Maximum time (seconds). Default is 3600.",
            action="store",
            dest="max_time",
            type=float,
            default=3600)
        conf_options_parser.add_argument(
            "--csvPrefix",
            help="Input file name prefix.  Default is ''",
            action="store",
            dest="csvPrefix",
            type=str,
            default="")
        conf_options_parser.add_argument(
            "--lambda-parm-name",
            help=
            "The name of the lambda parameter in the model. Default is lambdaMult",
            action="store",
            dest="lambda_parm_name",
            type=str,
            default="lambdaMult")
        conf_options_parser.add_argument(
            "--indicator-var-name",
            help=
            "The name of the indicator variable for the chance constraint. The default is delta",
            action="store",
            dest="indicator_var_name",
            type=str,
            default="delta")
        conf_options_parser.add_argument(
            "--stage-num",
            help=
            "The stage number of the CC indicator variable (number, not name). Default is 2",
            action="store",
            dest="stage_num",
            type=int,
            default=2)
        conf_options_parser.add_argument(
            "--verbosity",
            help=
            "verbosity=0 is no extra output, =1 is medium, =2 is debug, =3 super-debug. Default is 1.",
            action="store",
            dest="verbosity",
            type=int,
            default=1)
        conf_options_parser.add_argument(
            "--prob-file",
            help="file name specifiying probabilities",
            action="store",
            dest="probFileName",
            type=str,
            default=None)
        # The following needed for solve_ph_code in lagrangeutils
        conf_options_parser.add_argument(
            "--solve-with-ph",
            help=
            "Perform solves via PH rather than an EF solve. Default is False",
            action="store_true",
            dest="solve_with_ph",
            default=False)

        ################################################################

        options = conf_options_parser.parse_args(args=args)
        # temporary hack
        options._ef_options = conf_options_parser._ef_options
        options._ef_options.import_argparse(options)
    except SystemExit as _exc:
        # the parser throws a system exit if "-h" is specified - catch
        # it to exit gracefully.
        return _exc.code

    if options.verbose is True:
        print("Loading reference model and scenario tree")

    scenario_instance_factory = \
         ScenarioTreeInstanceFactory(options.model_directory,
                                     options.instance_directory)

    full_scenario_tree = \
             GenerateScenarioTreeForPH(options,
                                       scenario_instance_factory)

    solver_manager = SolverManagerFactory(options.solver_manager_type)
    if solver_manager is None:
        raise ValueError("Failed to create solver manager of "
                         "type=" + options.solver_manager_type +
                         " specified in call to PH constructor")
    if isinstance(solver_manager, pysp.plugins.phpyro.SolverManager_PHPyro):
        raise ValueError("PHPyro can not be used as the solver manager")

    try:

        if (scenario_instance_factory is None) or (full_scenario_tree is None):
            raise RuntimeError(
                "***ERROR: Failed to initialize the model and/or scenario tree data."
            )

        # load_model gets called again, so lets make sure unarchived directories are used
        options.model_directory = scenario_instance_factory._model_filename
        options.instance_directory = scenario_instance_factory._scenario_tree_filename

        scenario_count = len(full_scenario_tree._stages[-1]._tree_nodes)

        # create ph objects for finding the solution. we do this even if
        # we're solving the extensive form

        if options.verbose is True:
            print(
                "Loading scenario instances and initializing scenario tree for full problem."
            )

########## Here is where multiplier search is called ############
        Result = LagrangeMorePR()
#####################################################################################
    finally:
        # delete temporary unarchived directories
        scenario_instance_factory.close()

    print("\n====================  returned from LagrangeMorePR")
    print(str(Result.status))
    try:
        print("Envelope:")
        print(str(PrintPRpoints(Result.PRoptimal)))
        print("\nAdded:")
        PrintPRpoints(Result.morePR)
    except:
        print("from run:  PrintPRpoints failed")
        sys.exit()

# combine tables and sort by probability
    if len(Result.morePR) > 0:
        PRpoints = copy.deepcopy(Result.PRoptimal)
        for lbz in Result.morePR:
            PRpoints.append(lbz)
        print("Combined table of PR points (sorted):")
        PRpoints.sort(key=operator.itemgetter(1))
        print(str(PrintPRpoints(PRpoints)))