ROMAAssignments.cpp

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/****************************************************************************/
// Eclipse SUMO, Simulation of Urban MObility; see https://eclipse.dev/sumo
// Copyright (C) 2001-2026 German Aerospace Center (DLR) and others.
// This program and the accompanying materials are made available under the
// terms of the Eclipse Public License 2.0 which is available at
// https://www.eclipse.org/legal/epl-2.0/
// This Source Code may also be made available under the following Secondary
// Licenses when the conditions for such availability set forth in the Eclipse
// Public License 2.0 are satisfied: GNU General Public License, version 2
// or later which is available at
// https://www.gnu.org/licenses/old-licenses/gpl-2.0-standalone.html
// SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-or-later
/****************************************************************************/
// Assignment methods
/****************************************************************************/
#include <config.h>
 
#include <vector>
#include <algorithm>
#include <utils/common/SUMOTime.h>
#include <utils/distribution/Distribution_Points.h>
#include <utils/router/RouteCostCalculator.h>
#include <utils/router/SUMOAbstractRouter.h>
#include <router/ROEdge.h>
#include <router/RONet.h>
#include <router/RORoute.h>
#include <od/ODMatrix.h>
#include "ROMAEdge.h"
#include "ROMAAssignments.h"
 
 
// ===========================================================================
// static member variables
// ===========================================================================
std::map<const ROEdge* const, double> ROMAAssignments::myPenalties;
 
 
// ===========================================================================
// method definitions
// ===========================================================================
 
ROMAAssignments::ROMAAssignments(const SUMOTime begin, const SUMOTime end, const bool additiveTraffic,
                                 const double adaptionFactor, const int maxAlternatives, const bool defaultCapacities,
                                 RONet& net, ODMatrix& matrix, SUMOAbstractRouter<ROEdge, ROVehicle>& router,
                                 OutputDevice* netloadOutput)
    : myBegin(begin), myEnd(end), myAdditiveTraffic(additiveTraffic), myAdaptionFactor(adaptionFactor),
      myMaxAlternatives(maxAlternatives), myUseDefaultCapacities(defaultCapacities),
      myNet(net), myMatrix(matrix), myRouter(router), myNetloadOutput(netloadOutput) {
    myDefaultVehicle = new ROVehicle(SUMOVehicleParameter(), nullptr, net.getVehicleTypeSecure(DEFAULT_VTYPE_ID), &net);
}
 
 
ROMAAssignments::~ROMAAssignments() {
    delete myDefaultVehicle;
}
 
// based on the definitions in PTV-Validate and in the VISUM-Cologne network
double
ROMAAssignments::getCapacity(const ROEdge* edge) const {
    if (edge->isTazConnector()) {
        return 0;
    }
    const int roadClass = myUseDefaultCapacities ? -1 : -edge->getPriority();
    // TODO: differ road class 1 from the unknown road class 1!!!
    if (edge->getNumLanes() == 0) {
        // TAZ have no cost
        return 0;
    } else if (roadClass == 0 || roadClass == 1)  {
        return edge->getNumLanes() * 2000.; //CR13 in table.py
    } else if (roadClass == 2 && edge->getSpeedLimit() <= 11.) {
        return edge->getNumLanes() * 1333.33; //CR5 in table.py
    } else if (roadClass == 2 && edge->getSpeedLimit() > 11. && edge->getSpeedLimit() <= 16.) {
        return edge->getNumLanes() * 1500.; //CR3 in table.py
    } else if (roadClass == 2 && edge->getSpeedLimit() > 16.) {
        return edge->getNumLanes() * 2000.; //CR13 in table.py
    } else if (roadClass == 3 && edge->getSpeedLimit() <= 11.) {
        return edge->getNumLanes() * 800.; //CR5 in table.py
    } else if (roadClass == 3 && edge->getSpeedLimit() > 11. && edge->getSpeedLimit() <= 13.) {
        return edge->getNumLanes() * 875.; //CR5 in table.py
    } else if (roadClass == 3 && edge->getSpeedLimit() > 13. && edge->getSpeedLimit() <= 16.) {
        return edge->getNumLanes() * 1500.; //CR4 in table.py
    } else if (roadClass == 3 && edge->getSpeedLimit() > 16.) {
        return edge->getNumLanes() * 1800.; //CR13 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() <= 5.) {
        return edge->getNumLanes() * 200.; //CR7 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 5. && edge->getSpeedLimit() <= 7.) {
        return edge->getNumLanes() * 412.5; //CR7 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 7. && edge->getSpeedLimit() <= 9.) {
        return edge->getNumLanes() * 600.; //CR6 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 9. && edge->getSpeedLimit() <= 11.) {
        return edge->getNumLanes() * 800.; //CR5 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 11. && edge->getSpeedLimit() <= 13.) {
        return edge->getNumLanes() * 1125.; //CR5 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 13. && edge->getSpeedLimit() <= 16.) {
        return edge->getNumLanes() * 1583.; //CR4 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 16. && edge->getSpeedLimit() <= 18.) {
        return edge->getNumLanes() * 1100.; //CR3 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 18. && edge->getSpeedLimit() <= 22.) {
        return edge->getNumLanes() * 1200.; //CR3 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 22. && edge->getSpeedLimit() <= 26.) {
        return edge->getNumLanes() * 1300.; //CR3 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 26.) {
        return edge->getNumLanes() * 1400.; //CR3 in table.py
    }
    return edge->getNumLanes() * 800.; //CR5 in table.py
}
 
 
// based on the definitions in PTV-Validate and in the VISUM-Cologne network
double
ROMAAssignments::capacityConstraintFunction(const ROEdge* edge, const double flow) const {
    if (edge->isTazConnector()) {
        return 0;
    }
    const int roadClass = myUseDefaultCapacities ? -1 : -edge->getPriority();
    const double capacity = getCapacity(edge);
    // TODO: differ road class 1 from the unknown road class 1!!!
    if (edge->getNumLanes() == 0) {
        // TAZ have no cost
        return 0;
    } else if (roadClass == 0 || roadClass == 1)  {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 1.3)) * 2.); //CR13 in table.py
    } else if (roadClass == 2 && edge->getSpeedLimit() <= 11.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 0.9)) * 3.); //CR5 in table.py
    } else if (roadClass == 2 && edge->getSpeedLimit() > 11. && edge->getSpeedLimit() <= 16.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 1.)) * 2.); //CR3 in table.py
    } else if (roadClass == 2 && edge->getSpeedLimit() > 16.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 1.3)) * 2.); //CR13 in table.py
    } else if (roadClass == 3 && edge->getSpeedLimit() <= 11.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 0.9)) * 3.); //CR5 in table.py
    } else if (roadClass == 3 && edge->getSpeedLimit() > 11. && edge->getSpeedLimit() <= 13.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 0.9)) * 3.); //CR5 in table.py
    } else if (roadClass == 3 && edge->getSpeedLimit() > 13. && edge->getSpeedLimit() <= 16.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.7 * (flow / (capacity * 1.)) * 2.); //CR4 in table.py
    } else if (roadClass == 3 && edge->getSpeedLimit() > 16.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 1.3)) * 2.); //CR13 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() <= 5.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 0.5)) * 3.); //CR7 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 5. && edge->getSpeedLimit() <= 7.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 0.5)) * 3.); //CR7 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 7. && edge->getSpeedLimit() <= 9.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 0.8)) * 3.); //CR6 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 9. && edge->getSpeedLimit() <= 11.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 0.9)) * 3.); //CR5 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 11. && edge->getSpeedLimit() <= 13.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 0.9)) * 3.); //CR5 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 13. && edge->getSpeedLimit() <= 16.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.7 * (flow / (capacity * 1.)) * 2.); //CR4 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 16. && edge->getSpeedLimit() <= 18.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 1.)) * 2.); //CR3 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 18. && edge->getSpeedLimit() <= 22.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 1.)) * 2.); //CR3 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 22. && edge->getSpeedLimit() <= 26.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 1.)) * 2.); //CR3 in table.py
    } else if ((roadClass >= 4 || roadClass == -1) && edge->getSpeedLimit() > 26.) {
        return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 1.)) * 2.); //CR3 in table.py
    }
    return edge->getLength() / edge->getSpeedLimit() * (1. + 1.*(flow / (capacity * 0.9)) * 3.); //CR5 in table.py
}
 
 
bool
ROMAAssignments::addRoute(const ConstROEdgeVector& edges, std::vector<std::shared_ptr<RORoute> >& paths, std::string routeId, double prob) {
    std::vector<std::shared_ptr<RORoute> >::iterator p;
    for (p = paths.begin(); p != paths.end(); p++) {
        if (edges == (*p)->getEdgeVector()) {
            break;
        }
    }
    if (p == paths.end()) {
        paths.push_back(std::make_shared<RORoute>(routeId, 0., prob, edges, nullptr, StopParVector()));
        return true;
    }
    (*p)->addProbability(prob);
    std::iter_swap(paths.end() - 1, p);
    return false;
}
 
 
const ConstROEdgeVector
ROMAAssignments::computePath(ODCell* cell, const SUMOTime time, const double probability, SUMOAbstractRouter<ROEdge, ROVehicle>* router, bool setBulkMode) {
    const ROEdge* const from = myNet.getEdge(cell->origin + (cell->originIsEdge ? "" : "-source"));
    if (from == nullptr) {
        throw ProcessError(TLF("Unknown origin '%'.", cell->origin));
    }
    const ROEdge* const to = myNet.getEdge(cell->destination + (cell->destinationIsEdge ? "" : "-sink"));
    if (to == nullptr) {
        throw ProcessError(TLF("Unknown destination '%'.", cell->destination));
    }
    ConstROEdgeVector edges;
    if (router == nullptr) {
        router = &myRouter;
    }
    if (myMaxAlternatives > 0 && (int)cell->pathsVector.size() < myMaxAlternatives) {
        router->compute(from, to, myDefaultVehicle, time, edges);
        if (setBulkMode) {
            router->setBulkMode(true);
        }
        if (addRoute(edges, cell->pathsVector, cell->origin + cell->destination + toString(cell->pathsVector.size()), probability)) {
            return edges;
        }
    } else {
        double minCost = std::numeric_limits<double>::max();
        std::shared_ptr<RORoute> minRoute = nullptr;
        for (const std::shared_ptr<RORoute>& p : cell->pathsVector) {
            const double cost = router->recomputeCosts(edges, myDefaultVehicle, time);
            if (cost < minCost) {
                minCost = cost;
                minRoute = p;
            }
        }
        minRoute->addProbability(probability);
    }
    return ConstROEdgeVector();
}
 
 
void
ROMAAssignments::getKPaths(const int kPaths, const double penalty) {
    for (ODCell* const c : myMatrix.getCells()) {
        myPenalties.clear();
        for (int k = 0; k < kPaths; k++) {
            for (const ROEdge* const e : computePath(c)) {
                myPenalties[e] += penalty;
            }
        }
    }
    myPenalties.clear();
}
 
 
void
ROMAAssignments::resetFlows() {
    const double begin = STEPS2TIME(MIN2(myBegin, myMatrix.getCells().front()->begin));
    for (ROEdge* e : ROEdge::getAllEdges()) {
        ROMAEdge* const edge = static_cast<ROMAEdge*>(e);
        edge->setFlow(begin, STEPS2TIME(myEnd), 0.);
        edge->setHelpFlow(begin, STEPS2TIME(myEnd), 0.);
    }
}
 
 
void
ROMAAssignments::writeInterval(const SUMOTime begin, const SUMOTime end) {
    if (myNetloadOutput != nullptr) {
        myNetloadOutput->openTag(SUMO_TAG_INTERVAL).writeAttr(SUMO_ATTR_BEGIN, time2string(begin)).writeAttr(SUMO_ATTR_END, time2string(end));
        for (ROEdge* e : ROEdge::getAllEdges()) {
            const ROMAEdge* const edge = static_cast<ROMAEdge*>(e);
            if (edge->getFunction() == SumoXMLEdgeFunc::NORMAL) {
                myNetloadOutput->openTag(SUMO_TAG_EDGE).writeAttr(SUMO_ATTR_ID, edge->getID());
                const double traveltime = edge->getTravelTime(getDefaultVehicle(), STEPS2TIME(begin));
                const double speed = edge->getLength() / traveltime;
                const double flow = edge->getFlow(STEPS2TIME(begin));
                const double timeGap = STEPS2TIME(end - begin) / flow;
                const double spaceGap = timeGap * speed;
                const double density = 1000.0 / spaceGap;
                const double laneDensity = density / edge->getNumLanes();
                myNetloadOutput->writeAttr(SUMO_ATTR_TRAVELTIME, traveltime);
                myNetloadOutput->writeAttr(SUMO_ATTR_SPEED, speed);
                myNetloadOutput->writeAttr(SUMO_ATTR_SPEEDREL, speed / edge->getSpeedLimit());
                myNetloadOutput->writeAttr(SUMO_ATTR_ENTERED, flow);
                myNetloadOutput->writeAttr(SUMO_ATTR_DENSITY, density);
                myNetloadOutput->writeAttr(SUMO_ATTR_LANEDENSITY, laneDensity);
                myNetloadOutput->writeAttr("flowCapacityRatio", 100. * flow / getCapacity(edge));
                myNetloadOutput->closeTag();
            }
        }
        myNetloadOutput->closeTag();
    }
}
 
 
void
ROMAAssignments::incremental(const int numIter, const bool verbose) {
    SUMOTime lastBegin = -1;
    std::vector<int> intervals;
    int count = 0;
    for (const ODCell* const c : myMatrix.getCells()) {
        if (c->begin != lastBegin) {
            intervals.push_back(count);
            lastBegin = c->begin;
        }
        count++;
    }
    lastBegin = -1;
    for (std::vector<int>::const_iterator offset = intervals.begin(); offset != intervals.end(); offset++) {
        std::vector<ODCell*>::const_iterator firstCell = myMatrix.getCells().begin() + (*offset);
        std::vector<ODCell*>::const_iterator lastCell = myMatrix.getCells().end();
        if (offset != intervals.end() - 1) {
            lastCell = myMatrix.getCells().begin() + (*(offset + 1));
        }
        const SUMOTime intervalStart = (*firstCell)->begin;
        if (verbose) {
            WRITE_MESSAGE(" starting interval " + time2string(intervalStart));
        }
        std::map<const ROMAEdge*, double> loadedTravelTimes;
        for (ROEdge* e : ROEdge::getAllEdges()) {
            const ROMAEdge* const edge = static_cast<ROMAEdge*>(e);
            if (edge->hasLoadedTravelTime(STEPS2TIME(intervalStart))) {
                loadedTravelTimes[edge] = edge->getTravelTime(myDefaultVehicle, STEPS2TIME(intervalStart));
            }
        }
        if (loadedTravelTimes.empty()) {
            // we don't have loaded travel times for this interval but we may have set ourselves some for the interval before but no need to warn
            ROEdge::disableTimelineWarning();
        }
        for (int t = 0; t < numIter; t++) {
            if (verbose) {
                WRITE_MESSAGE("  starting iteration " + toString(t));
            }
            std::string lastOrigin = "";
            int workerIndex = 0;
            for (std::vector<ODCell*>::const_iterator i = firstCell; i != lastCell; i++) {
                ODCell* const c = *i;
                const double linkFlow = c->vehicleNumber / numIter;
                const SUMOTime begin = myAdditiveTraffic ? myBegin : c->begin;
#ifdef HAVE_FOX
                if (myNet.getThreadPool().size() > 0) {
                    if (lastOrigin != c->origin) {
                        workerIndex++;
                        if (workerIndex == myNet.getThreadPool().size()) {
                            workerIndex = 0;
                        }
                        myNet.getThreadPool().add(new RONet::BulkmodeTask(false), workerIndex);
                        lastOrigin = c->origin;
                        myNet.getThreadPool().add(new RoutingTask(*this, c, begin, linkFlow), workerIndex);
                    } else {
                        myNet.getThreadPool().add(new RoutingTask(*this, c, begin, linkFlow), workerIndex);
                    }
                    continue;
                }
#else
                UNUSED_PARAMETER(workerIndex);
#endif
                if (lastOrigin != c->origin) {
                    myRouter.setBulkMode(false);
                    lastOrigin = c->origin;
                }
                computePath(c, begin, linkFlow, &myRouter, true);
            }
#ifdef HAVE_FOX
            if (myNet.getThreadPool().size() > 0) {
                myNet.getThreadPool().waitAll();
            }
#endif
            for (std::vector<ODCell*>::const_iterator i = firstCell; i != lastCell; i++) {
                ODCell* const c = *i;
                const double linkFlow = c->vehicleNumber / numIter;
                const SUMOTime begin = myAdditiveTraffic ? myBegin : c->begin;
                const SUMOTime end = myAdditiveTraffic ? myEnd : c->end;
                const double intervalLengthInHours = STEPS2TIME(end - begin) / 3600.;
                const ConstROEdgeVector& edges = c->pathsVector.back()->getEdgeVector();
                for (ConstROEdgeVector::const_iterator e = edges.begin(); e != edges.end(); e++) {
                    ROMAEdge* edge = static_cast<ROMAEdge*>(myNet.getEdge((*e)->getID()));
                    const double newFlow = edge->getFlow(STEPS2TIME(begin)) + linkFlow;
                    edge->setFlow(STEPS2TIME(begin), STEPS2TIME(end), newFlow);
                    double travelTime = capacityConstraintFunction(edge, newFlow / intervalLengthInHours);
                    if (lastBegin >= 0 && myAdaptionFactor > 0.) {
                        if (loadedTravelTimes.count(edge) != 0) {
                            travelTime = loadedTravelTimes[edge] * myAdaptionFactor + (1. - myAdaptionFactor) * travelTime;
                        } else {
                            travelTime = edge->getTravelTime(myDefaultVehicle, STEPS2TIME(lastBegin)) * myAdaptionFactor + (1. - myAdaptionFactor) * travelTime;
                        }
                    }
                    edge->addTravelTime(travelTime, STEPS2TIME(begin), STEPS2TIME(end));
                }
            }
            myRouter.reset(myDefaultVehicle);
        }
        writeInterval(intervalStart, (*(lastCell - 1))->end);
        lastBegin = intervalStart;
    }
}
 
 
void
ROMAAssignments::sue(const int maxOuterIteration, const int maxInnerIteration, const int kPaths, const double penalty, const double tolerance, const std::string /* routeChoiceMethod */) {
    getKPaths(kPaths, penalty);
    std::map<const SUMOTime, SUMOTime> intervals;
    if (myAdditiveTraffic) {
        intervals[myBegin] = myEnd;
    } else {
        for (const ODCell* const c : myMatrix.getCells()) {
            intervals[c->begin] = c->end;
        }
    }
    for (int outer = 0; outer < maxOuterIteration; outer++) {
        for (int inner = 0; inner < maxInnerIteration; inner++) {
            for (const ODCell* const c : myMatrix.getCells()) {
                const SUMOTime begin = myAdditiveTraffic ? myBegin : c->begin;
                const SUMOTime end = myAdditiveTraffic ? myEnd : c->end;
                // update path cost
                for (const std::shared_ptr<RORoute>& r : c->pathsVector) {
                    r->setCosts(myRouter.recomputeCosts(r->getEdgeVector(), myDefaultVehicle, 0));
                    //                    std::cout << std::setprecision(20) << r->getID() << ":" << r->getCosts() << std::endl;
                }
                // calculate route utilities and probabilities
                RouteCostCalculator<RORoute, ROEdge, ROVehicle>::getCalculator().calculateProbabilities(c->pathsVector, myDefaultVehicle, 0);
                // calculate route flows
                for (const std::shared_ptr<RORoute>& r : c->pathsVector) {
                    const double pathFlow = r->getProbability() * c->vehicleNumber;
                    // assign edge flow deltas
                    for (ConstROEdgeVector::const_iterator e = r->getEdgeVector().begin(); e != r->getEdgeVector().end(); e++) {
                        ROMAEdge* edge = static_cast<ROMAEdge*>(myNet.getEdge((*e)->getID()));
                        edge->setHelpFlow(STEPS2TIME(begin), STEPS2TIME(end), edge->getHelpFlow(STEPS2TIME(begin)) + pathFlow);
                    }
                }
            }
            // calculate new edge flows and check for stability
            int unstableEdges = 0;
            for (const auto& it : intervals) {
                const double intervalLengthInHours = STEPS2TIME(it.second - it.first) / 3600.;
                const double intBegin = STEPS2TIME(it.first);
                const double intEnd = STEPS2TIME(it.second);
                for (ROEdge* e : ROEdge::getAllEdges()) {
                    ROMAEdge* const edge = static_cast<ROMAEdge*>(e);
                    const double oldFlow = edge->getFlow(intBegin);
                    double newFlow = oldFlow;
                    if (inner == 0 && outer == 0) {
                        newFlow += edge->getHelpFlow(intBegin);
                    } else {
                        newFlow += (edge->getHelpFlow(intBegin) - oldFlow) / (inner + 1);
                    }
                    //                if not lohse:
                    if (newFlow > 0.) {
                        if (fabs(newFlow - oldFlow) / newFlow > tolerance) {
                            unstableEdges++;
                        }
                    } else if (newFlow == 0.) {
                        if (oldFlow != 0. && (fabs(newFlow - oldFlow) / oldFlow > tolerance)) {
                            unstableEdges++;
                        }
                    } else { // newFlow < 0.
                        unstableEdges++;
                        newFlow = 0.;
                    }
                    edge->setFlow(intBegin, intEnd, newFlow);
                    const double travelTime = capacityConstraintFunction(edge, newFlow / intervalLengthInHours);
                    edge->addTravelTime(travelTime, intBegin, intEnd);
                    edge->setHelpFlow(intBegin, intEnd, 0.);
                }
            }
            // if stable break
            if (unstableEdges == 0) {
                break;
            }
            // additional stability check from python script: if notstable < math.ceil(net.geteffEdgeCounts()*0.005) or notstable < 3: stable = True
        }
        // check for a new route, if none available, break
        // several modifications about when a route is new and when to break are in the original script
        bool newRoute = false;
        for (ODCell* const c : myMatrix.getCells()) {
            newRoute |= !computePath(c).empty();
        }
        if (!newRoute) {
            break;
        }
    }
    // final round of assignment
    for (const ODCell* const c : myMatrix.getCells()) {
        // update path cost
        for (const std::shared_ptr<RORoute>& r : c->pathsVector) {
            r->setCosts(myRouter.recomputeCosts(r->getEdgeVector(), myDefaultVehicle, 0));
        }
        // calculate route utilities and probabilities
        RouteCostCalculator<RORoute, ROEdge, ROVehicle>::getCalculator().calculateProbabilities(c->pathsVector, myDefaultVehicle, 0);
        // calculate route flows
        for (const std::shared_ptr<RORoute>& r : c->pathsVector) {
            r->setProbability(r->getProbability() * c->vehicleNumber);
        }
    }
    for (const auto& it : intervals) {
        writeInterval(it.first, it.second);
    }
}
 
 
double
ROMAAssignments::getPenalizedEffort(const ROEdge* const e, const ROVehicle* const v, double t) {
    const std::map<const ROEdge* const, double>::const_iterator i = myPenalties.find(e);
    return i == myPenalties.end() ? e->getEffort(v, t) : e->getEffort(v, t) + i->second;
}
 
 
double
ROMAAssignments::getPenalizedTT(const ROEdge* const e, const ROVehicle* const v, double t) {
    const std::map<const ROEdge* const, double>::const_iterator i = myPenalties.find(e);
    return i == myPenalties.end() ? e->getTravelTime(v, t) : e->getTravelTime(v, t) + i->second;
}
 
 
double
ROMAAssignments::getTravelTime(const ROEdge* const e, const ROVehicle* const v, double t) {
    return e->getTravelTime(v, t);
}
 
 
#ifdef HAVE_FOX
// ---------------------------------------------------------------------------
// ROMAAssignments::RoutingTask-methods
// ---------------------------------------------------------------------------
void
ROMAAssignments::RoutingTask::run(MFXWorkerThread* context) {
    myAssign.computePath(myCell, myBegin, myLinkFlow, &static_cast<RONet::WorkerThread*>(context)->getVehicleRouter(SVC_IGNORING), mySetBulkMode);
}
#endif