void
ROGawronCalculator::calculateProbabilities(std::vector<RORoute*> alternatives, const ROVehicle* const /* veh */, const SUMOTime /* time */) {
for (std::vector<RORoute*>::iterator i = alternatives.begin(); i != alternatives.end() - 1; i++) {
RORoute* pR = *i;
for (std::vector<RORoute*>::iterator j = i + 1; j != alternatives.end(); j++) {
RORoute* pS = *j;
// see [Gawron, 1998] (4.2)
const SUMOReal delta =
(pS->getCosts() - pR->getCosts()) /
(pS->getCosts() + pR->getCosts());
// see [Gawron, 1998] (4.3a, 4.3b)
SUMOReal newPR = gawronF(pR->getProbability(), pS->getProbability(), delta);
SUMOReal newPS = pR->getProbability() + pS->getProbability() - newPR;
if (ISNAN(newPR) || ISNAN(newPS)) {
newPR = pS->getCosts() > pR->getCosts()
? (SUMOReal) 1. : 0;
newPS = pS->getCosts() > pR->getCosts()
? 0 : (SUMOReal) 1.;
}
newPR = MIN2((SUMOReal) MAX2(newPR, (SUMOReal) 0), (SUMOReal) 1);
newPS = MIN2((SUMOReal) MAX2(newPS, (SUMOReal) 0), (SUMOReal) 1);
pR->setProbability(newPR);
pS->setProbability(newPS);
}
}
}
void
ROLogitCalculator::calculateProbabilities(std::vector<RORoute*> alternatives, const ROVehicle* const veh, const SUMOTime time) {
const SUMOReal theta = myTheta >= 0 ? myTheta : getThetaForCLogit(alternatives);
const SUMOReal beta = myBeta >= 0 ? myBeta : getBetaForCLogit(alternatives);
if (beta > 0) {
// calculate commonalities
for (std::vector<RORoute*>::const_iterator i = alternatives.begin(); i != alternatives.end(); i++) {
const RORoute* pR = *i;
SUMOReal lengthR = 0;
const std::vector<const ROEdge*>& edgesR = pR->getEdgeVector();
for (std::vector<const ROEdge*>::const_iterator edge = edgesR.begin(); edge != edgesR.end(); ++edge) {
//@todo we should use costs here
lengthR += (*edge)->getTravelTime(veh, STEPS2TIME(time));
}
SUMOReal overlapSum = 0;
for (std::vector<RORoute*>::const_iterator j = alternatives.begin(); j != alternatives.end(); j++) {
const RORoute* pS = *j;
SUMOReal overlapLength = 0.;
SUMOReal lengthS = 0;
const std::vector<const ROEdge*>& edgesS = pS->getEdgeVector();
for (std::vector<const ROEdge*>::const_iterator edge = edgesS.begin(); edge != edgesS.end(); ++edge) {
lengthS += (*edge)->getTravelTime(veh, STEPS2TIME(time));
if (std::find(edgesR.begin(), edgesR.end(), *edge) != edgesR.end()) {
overlapLength += (*edge)->getTravelTime(veh, STEPS2TIME(time));
}
}
overlapSum += pow(overlapLength / sqrt(lengthR * lengthS), myGamma);
}
myCommonalities[pR] = beta * log(overlapSum);
}
}
for (std::vector<RORoute*>::iterator i = alternatives.begin(); i != alternatives.end(); i++) {
RORoute* pR = *i;
SUMOReal weightedSum = 0;
for (std::vector<RORoute*>::iterator j = alternatives.begin(); j != alternatives.end(); j++) {
RORoute* pS = *j;
weightedSum += exp(theta * (pR->getCosts() - pS->getCosts() + myCommonalities[pR] - myCommonalities[pS]));
}
pR->setProbability(1. / weightedSum);
}
}
void
RORouteDef::addAlternative(SUMOAbstractRouter<ROEdge, ROVehicle>& router,
const ROVehicle* const veh, RORoute* current, SUMOTime begin) {
if (myTryRepair) {
if (myNewRoute) {
delete myAlternatives[0];
myAlternatives.pop_back();
myAlternatives.push_back(current);
}
const SUMOReal costs = router.recomputeCosts(current->getEdgeVector(), veh, begin);
if (costs < 0) {
throw ProcessError("Route '" + getID() + "' (vehicle '" + veh->getID() + "') is not valid.");
}
current->setCosts(costs);
return;
}
// add the route when it's new
if (myNewRoute) {
myAlternatives.push_back(current);
}
// recompute the costs and (when a new route was added) scale the probabilities
const SUMOReal scale = SUMOReal(myAlternatives.size() - 1) / SUMOReal(myAlternatives.size());
for (std::vector<RORoute*>::iterator i = myAlternatives.begin(); i != myAlternatives.end(); i++) {
RORoute* alt = *i;
// recompute the costs for all routes
const SUMOReal newCosts = router.recomputeCosts(alt->getEdgeVector(), veh, begin);
if (newCosts < 0.) {
throw ProcessError("Route '" + current->getID() + "' (vehicle '" + veh->getID() + "') is not valid.");
}
assert(myAlternatives.size() != 0);
if (myNewRoute) {
if (*i == current) {
// set initial probability and costs
alt->setProbability((SUMOReal)(1.0 / (SUMOReal) myAlternatives.size()));
alt->setCosts(newCosts);
} else {
// rescale probs for all others
alt->setProbability(alt->getProbability() * scale);
}
}
ROCostCalculator::getCalculator().setCosts(alt, newCosts, *i == myAlternatives[myLastUsed]);
}
assert(myAlternatives.size() != 0);
ROCostCalculator::getCalculator().calculateProbabilities(veh, myAlternatives);
if (!ROCostCalculator::getCalculator().keepRoutes()) {
// remove with probability of 0 (not mentioned in Gawron)
for (std::vector<RORoute*>::iterator i = myAlternatives.begin(); i != myAlternatives.end();) {
if ((*i)->getProbability() == 0) {
delete *i;
i = myAlternatives.erase(i);
} else {
i++;
}
}
}
if (myAlternatives.size() > ROCostCalculator::getCalculator().getMaxRouteNumber()) {
// only keep the routes with highest probability
sort(myAlternatives.begin(), myAlternatives.end(), ComparatorProbability());
for (std::vector<RORoute*>::iterator i = myAlternatives.begin() + ROCostCalculator::getCalculator().getMaxRouteNumber(); i != myAlternatives.end(); i++) {
delete *i;
}
myAlternatives.erase(myAlternatives.begin() + ROCostCalculator::getCalculator().getMaxRouteNumber(), myAlternatives.end());
// rescale probabilities
SUMOReal newSum = 0;
for (std::vector<RORoute*>::iterator i = myAlternatives.begin(); i != myAlternatives.end(); i++) {
newSum += (*i)->getProbability();
}
assert(newSum > 0);
// @note newSum may be larger than 1 for numerical reasons
for (std::vector<RORoute*>::iterator i = myAlternatives.begin(); i != myAlternatives.end(); i++) {
(*i)->setProbability((*i)->getProbability() / newSum);
}
}
// find the route to use
SUMOReal chosen = RandHelper::rand();
int pos = 0;
for (std::vector<RORoute*>::iterator i = myAlternatives.begin(); i != myAlternatives.end() - 1; i++, pos++) {
chosen -= (*i)->getProbability();
if (chosen <= 0) {
myLastUsed = pos;
return;
}
}
myLastUsed = pos;
}