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faster shapevl

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This commit is contained in:
Patrick Brosi 2022-01-12 17:20:10 +01:00
parent 1febc192ce
commit 1e516f4d2b
3 changed files with 61 additions and 54 deletions
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83
src/shapevl/Collector.cpp
View file

@ -96,23 +96,23 @@ double Collector::add(const Trip* oldT, const Shape* oldS, const Trip* newT,
double SEGL = 10;
if (_dCache.count(oldS) && _dCache.find(oldS)->second.count(newS->getId())) {
fd = _dCache[oldS][newS->getId()];
auto old = _dCache.find(oldLCut);
if (old != _dCache.end()) {
auto match = old->second.find(newLCut);
if (match != old->second.end()) {
fd = match->second;
} else {
fd = util::geo::accFrechetDistC(oldLCut, newLCut, SEGL / fac) * fac;
_dCache[oldLCut][newLCut] = fd;
}
} else {
fd = util::geo::accFrechetDistC(oldLCut, newLCut, SEGL / fac) * fac;
_dCache[oldS][newS->getId()] = fd;
_dCache[oldLCut][newLCut] = fd;
}
if (_dACache.count(oldS) &&
_dACache.find(oldS)->second.count(newS->getId())) {
unmatchedSegments = _dACache[oldS][newS->getId()].first;
unmatchedSegmentsLength = _dACache[oldS][newS->getId()].second;
} else {
auto dA = getDa(oldSegs, newSegs);
_dACache[oldS][newS->getId()] = dA;
unmatchedSegments = dA.first;
unmatchedSegmentsLength = dA.second;
}
auto dA = getDa(oldSegs, newSegs);
unmatchedSegments = dA.first;
unmatchedSegmentsLength = dA.second;
double totL = 0;
for (auto l : oldSegs) totL += util::geo::len(l) * fac;
@ -161,31 +161,6 @@ double Collector::add(const Trip* oldT, const Shape* oldS, const Trip* newT,
std::vector<LINE> Collector::segmentize(
const Trip* t, const LINE& shape, const std::vector<double>& dists,
std::vector<std::pair<double, double>>& lenDist) {
// The straightforward way to segmentize the shape would be to just cut it at
// the exact measurements in stop_times.txt. We have tried that, but found
// that it produces misleading results for the following reason:
//
// 1) The measurement specifies an exact position on the shape.
// 2) Even if we consider correct rail or bus tracks, the "right" position
// where a vehicle may come to a halt is not a point - its a line segment,
// basically the entire track in railroad term
// 3) The position point on the shape in real-world feeds may be either a) the
// position where a train comes to a halt, b) the position where a carriage
// comes to a halt, c) the beginning of the tracks line segment, d) the end
// of the tracks line segment, e) the center of the tracks line segment, f)
// ... (any position on the tracks line segment.
// 4) The "correct" position is NOT well-defined.
// 5) As tracks are often longer than 20 meters, this will dillute our AN
// measure, although the shape is CORRECT (because the ground truth uses
// a different position philosophy than the test data)
// 6) To normalize this, we use the following approach:
// a) Get the exact progression of the measurment on the shape
// b) Extract a segment of 200 meters, with the measurement progress in
// the middle c) Project the GROUND TRUTH station coordinate to this
// segment d) The result is the cutting point
// 7) If a completely wrong track was chosen, the frechet distance will still
// be greater than 20 meters and AN will measure an unmatch.
// 8) TODO: implement this, explain this in diss
std::vector<LINE> ret;
if (t->getStopTimes().size() < 2) return ret;
@ -218,9 +193,9 @@ std::vector<LINE> Collector::segmentize(
dists.begin();
}
POLYLINE beforePl(LINE(shape.begin(), shape.begin() + before));
POLYLINE afterPl(LINE(shape.begin(), shape.begin() + before));
auto curLp = beforePl.projectOnAfter(cuts[i].first, lastLp.lastIndex);
auto curLp = afterPl.projectOnAfter(cuts[i].first, lastLp.lastIndex);
auto curL = pl.getSegment(lastLp, curLp).getLine();
@ -431,16 +406,30 @@ std::pair<size_t, double> Collector::getDa(const std::vector<LINE>& a,
// euclidean distance on web mercator is in meters on equator,
// and proportional to cos(lat) in both y directions
double fac =
cos(2 * atan(exp((a.front().front().getY() + a.back().back().getY()) /
6378137.0)) -
1.5707965);
double fac = webMercDistFactor(a.front().front());
double SEGL = 10;
for (size_t i = 0; i < a.size(); i++) {
double fd = util::geo::frechetDist(a[i], b[i], 3 / fac) * fac;
if (fd >= 20) {
double fd = 0;
auto old = _dACache.find(a[i]);
if (old != _dACache.end()) {
auto match = old->second.find(b[i]);
if (match != old->second.end()) {
fd = match->second;
} else {
fd = util::geo::frechetDist(a[i], b[i], SEGL / fac) * fac;
_dACache[a[i]][b[i]] = fd;
}
} else {
fd = util::geo::frechetDist(a[i], b[i], SEGL / fac) * fac;
_dACache[a[i]][b[i]] = fd;
}
if (fd >= 50) {
ret.first++;
ret.second += util::geo::len(a[i]) * fac;
ret.second += util::geo::webMercLen(a[i]) * 100;
}
}

30
src/shapevl/Collector.h
View file

@ -24,6 +24,22 @@ using ad::cppgtfs::gtfs::Trip;
namespace pfaedle {
namespace eval {
struct lineCmp {
bool operator()(const LINE& a, const LINE& b) const {
if (a.size() != b.size()) {
return a.size() < b.size();
}
for (size_t i = 0; i < a.size(); i++) {
if (util::geo::dist(a[i], b[i]) > .1) {
return (a[i].getX() < b[i].getX()) || (a[i].getX() == b[i].getX() && a[i].getY() < b[i].getY());;
}
}
return false;
}
};
/*
* Collects routing results for evaluation
*/
@ -73,9 +89,9 @@ class Collector {
private:
std::set<Result> _results;
std::map<const Shape*, std::map<std::string, double> > _dCache;
std::map<const Shape*, std::map<std::string, std::pair<size_t, double> > >
_dACache;
std::map<LINE, std::map<LINE, double, lineCmp>, lineCmp> _dCache;
std::map<LINE, std::map<LINE, double, lineCmp>, lineCmp> _dACache;
size_t _trips;
size_t _noOrigShp;
@ -95,12 +111,12 @@ class Collector {
std::ostream* _reportOut;
static std::pair<size_t, double> getDa(const std::vector<LINE>& a,
std::pair<size_t, double> getDa(const std::vector<LINE>& a,
const std::vector<LINE>& b);
static std::vector<LINE> segmentize(const Trip* t, const LINE& shape,
const std::vector<double>& dists,
std::vector<std::pair<double, double>>& lenDist);
static std::vector<LINE> segmentize(
const Trip* t, const LINE& shape, const std::vector<double>& dists,
std::vector<std::pair<double, double>>& lenDist);
static std::vector<double> getBins(double mind, double maxd, size_t steps);
};

2
src/shapevl/ShapevlMain.cpp
View file

@ -56,7 +56,9 @@ void eval(const std::vector<std::string>* paths,
}
LOG(DEBUG) << "Evaluating " << path << "...";
size_t i = 0;
for (const auto& oldTrip : evalFeed->getTrips()) {
LOG(DEBUG) << "@ " << ++i << "/" << evalFeed->getTrips().size();
if (!mots->count(oldTrip.second->getRoute()->getType())) continue;
auto newTrip = feed.getTrips().get(oldTrip.first);
if (!newTrip) {