check for zero-speed due to missing wind or polar data; extend get-even-timed-path for the case of two cornerpoints per step; scale turning step of finish-phase 1-turner to layline; fix plausibility check;

2026-09-22 13:45:42 +00:00 · 2015-04-29 09:36:00 +02:00
parent 4c97142b8d
commit 3e69f05216
14 changed files with 123 additions and 96 deletions
@@ -403,7 +403,7 @@ import com.sap.sailing.simulator.PolarDiagram;
 import com.sap.sailing.simulator.SimulationResults;
 import com.sap.sailing.simulator.TimedPositionWithSpeed;
 import com.sap.sailing.simulator.impl.PolarDiagramGPS;
-import com.sap.sailing.simulator.impl.SparsePolarDataException;
+import com.sap.sailing.simulator.impl.SparseSimulationDataException;
 import com.sap.sailing.xrr.schema.RegattaResults;
 import com.sap.sailing.xrr.structureimport.SeriesParameters;
 import com.sap.sailing.xrr.structureimport.StructureImporter;
@@ -1434,7 +1434,7 @@ public class SailingServiceImpl extends ProxiedRemoteServiceServlet implements S
            PolarDiagram polarDiagram;
            try {
                polarDiagram = new PolarDiagramGPS(boatClass, polarData);
-            } catch (SparsePolarDataException e) {
+            } catch (SparseSimulationDataException e) {
                polarDiagram = null;
                // TODO: raise a UI message, to inform user about missing polar data resulting in unability to simulate
            }
@@ -49,7 +49,7 @@ import com.sap.sailing.simulator.Simulator;
 import com.sap.sailing.simulator.impl.PolarDiagramGPS;
 import com.sap.sailing.simulator.impl.SimulationParametersImpl;
 import com.sap.sailing.simulator.impl.SimulatorImpl;
-import com.sap.sailing.simulator.impl.SparsePolarDataException;
+import com.sap.sailing.simulator.impl.SparseSimulationDataException;
 import com.sap.sailing.simulator.util.SailingSimulatorConstants;
 import com.sap.sailing.simulator.windfield.WindFieldGenerator;
 import com.sap.sailing.simulator.windfield.impl.WindFieldTrackedRaceImpl;
@@ -391,7 +391,7 @@ public class SimulationServiceImpl implements SimulationService {
            PolarDiagram polarDiagram;
            try {
                polarDiagram = new PolarDiagramGPS(boatClass, polarDataService);
-            } catch (SparsePolarDataException e) {
+            } catch (SparseSimulationDataException e) {
                polarDiagram = null;
                // TODO: raise a UI message, to inform user about missing polar data resulting in unability to simulate
            }
@@ -441,19 +441,21 @@ public class SimulationServiceImpl implements SimulationService {
        }

        // collect 1-turner results
-        result.put(PathType.ONE_TURNER_LEFT, task1TurnerLeft.get());
-        result.put(PathType.ONE_TURNER_RIGHT, task1TurnerRight.get());
+        Path path1TurnerLeft = task1TurnerLeft.get();
+        result.put(PathType.ONE_TURNER_LEFT, path1TurnerLeft);
+        Path path1TurnerRight = task1TurnerRight.get();
+        result.put(PathType.ONE_TURNER_RIGHT, path1TurnerRight);

        if (simulationParameters.showOpportunist()) {
            // collect opportunist results
            Path pathOpportunistLeft = taskOpportunistLeft.get();
-            if (pathOpportunistLeft.getTurnCount() == 1) {
-                pathOpportunistLeft = result.get(PathType.ONE_TURNER_LEFT);
+            if (!path1TurnerLeft.getAlgorithmTimedOut() && (pathOpportunistLeft.getTurnCount() == 1)) {
+                pathOpportunistLeft = path1TurnerLeft;
            }
            result.put(PathType.OPPORTUNIST_LEFT, pathOpportunistLeft);
            Path pathOpportunistRight = taskOpportunistRight.get();
-            if (pathOpportunistRight.getTurnCount() == 1) {
-                pathOpportunistRight = result.get(PathType.ONE_TURNER_RIGHT);
+            if (!path1TurnerRight.getAlgorithmTimedOut() && (pathOpportunistRight.getTurnCount() == 1)) {
+                pathOpportunistRight = path1TurnerRight;
            }
            result.put(PathType.OPPORTUNIST_RIGHT, pathOpportunistRight);
        }
@@ -461,11 +463,11 @@ public class SimulationServiceImpl implements SimulationService {
        if (simulationParameters.showOmniscient()) {
            // collect omniscient result (last, since usually slowest calculation)
            Path pathOmniscient = taskOmniscient.get();
-            if (pathOmniscient.getFinalTime().after(result.get(PathType.ONE_TURNER_LEFT).getFinalTime())) {
-                pathOmniscient = result.get(PathType.ONE_TURNER_LEFT);
+            if (!path1TurnerLeft.getAlgorithmTimedOut() && (pathOmniscient.getFinalTime().after(path1TurnerLeft.getFinalTime()))) {
+                pathOmniscient = path1TurnerLeft;
            }
-            if (pathOmniscient.getFinalTime().after(result.get(PathType.ONE_TURNER_RIGHT).getFinalTime())) {
-                pathOmniscient = result.get(PathType.ONE_TURNER_RIGHT);
+            if (!path1TurnerRight.getAlgorithmTimedOut() && (pathOmniscient.getFinalTime().after(path1TurnerRight.getFinalTime()))) {
+                pathOmniscient = path1TurnerRight;
            }
            result.put(PathType.OMNISCIENT, pathOmniscient);
        }
@@ -21,7 +21,7 @@ import com.sap.sailing.simulator.impl.PolarDiagram49STG;
 import com.sap.sailing.simulator.impl.RectangularGrid;
 import com.sap.sailing.simulator.impl.SimulationParametersImpl;
 import com.sap.sailing.simulator.impl.SimulatorImpl;
-import com.sap.sailing.simulator.impl.SparsePolarDataException;
+import com.sap.sailing.simulator.impl.SparseSimulationDataException;
 import com.sap.sailing.simulator.util.SailingSimulatorConstants;
 import com.sap.sailing.simulator.windfield.WindControlParameters;
 import com.sap.sailing.simulator.windfield.WindFieldGenerator;
@@ -34,7 +34,7 @@ import com.sap.sse.common.impl.MillisecondsTimePoint;
 public class SimulatorTest {

    @Test
-    public void testSailingSimulatorALL() throws SparsePolarDataException {
+    public void testSailingSimulatorALL() throws SparseSimulationDataException {

        // race course: copacabana, rio de janeiro, brasil
        Position start = new DegreePosition(-22.975779, -43.17421);
@@ -1,6 +1,6 @@
 package com.sap.sailing.simulator;

-import com.sap.sailing.simulator.impl.SparsePolarDataException;
+import com.sap.sailing.simulator.impl.SparseSimulationDataException;

 public interface PathGenerator {

@@ -8,9 +8,9 @@ public interface PathGenerator {

    SimulationParameters getSimulationParameters();

-    Path getPath() throws SparsePolarDataException;
+    Path getPath() throws SparseSimulationDataException;

-    Path getPathEvenTimed(long stepMilliseconds) throws SparsePolarDataException;
+    Path getPathEvenTimed(long stepMilliseconds) throws SparseSimulationDataException;
    
    public boolean isTimedOut();

@@ -2,7 +2,7 @@ package com.sap.sailing.simulator;

 import java.util.List;

-import com.sap.sailing.simulator.impl.SparsePolarDataException;
+import com.sap.sailing.simulator.impl.SparseSimulationDataException;


 public interface Simulator {
@@ -11,7 +11,7 @@ public interface Simulator {

    SimulationParameters getSimulationParameters();

-    Path getPath(PathType pathType) throws SparsePolarDataException;
+    Path getPath(PathType pathType) throws SparseSimulationDataException;
    
    Path getRaceCourse();

@@ -92,7 +92,6 @@ public class PathGenerator1Turner360 extends PathGeneratorBase {
        long turnloss = polarDiagram.getTurnLoss(); // 4000;

        Distance courseLength = posStart.getDistance(posEnd);
-        Bearing bearStart2End = posStart.getBearingGreatCircle(posEnd);
        Position currentPosition = posStart;
        TimePoint currentTime = startTime;
        TimePoint nextTime;
@@ -109,7 +108,6 @@ public class PathGenerator1Turner360 extends PathGeneratorBase {
        } else {
            stepMax = this.evalStepMax;
        }
-        double[] reachTime = new double[stepMax];
        boolean targetFound;
        long timeStep;
        if (this.evalTimeStep == 0) {
@@ -118,11 +116,10 @@ public class PathGenerator1Turner360 extends PathGeneratorBase {
            timeStep = this.evalTimeStep;
        }
        Bearing direction;
+        Bearing layline;

        double newDistance;
        double minimumDistance = courseLength.getMeters();
-        //double overallMinimumDistance = courseLength.getMeters();
-        //int stepOfOverallMinimumDistance = stepMax;
        LinkedList<TimedPositionWithSpeed> path = null;
        LinkedList<TimedPositionWithSpeed> allminpath = null;
        TimePoint minimumTime = startTime.plus(24*60*60*1000);
@@ -130,7 +127,6 @@ public class PathGenerator1Turner360 extends PathGeneratorBase {

            currentPosition = posStart;
            currentTime = startTime;
-            reachTime[step] = courseLength.getMeters();
            targetFound = false;
            minimumDistance = courseLength.getMeters();
            path = new LinkedList<TimedPositionWithSpeed>();
@@ -159,19 +155,24 @@ public class PathGenerator1Turner360 extends PathGeneratorBase {
                    if (pointOfSail == PointOfSail.TACKING) {
                        if (leftSide) {
                            direction = polarDiagram.optimalDirectionsUpwind()[0];
+                            layline = polarDiagram.optimalDirectionsUpwind()[1].reverse();
                        } else {
                            direction = polarDiagram.optimalDirectionsUpwind()[1];
+                            layline = polarDiagram.optimalDirectionsUpwind()[0].reverse();
                        }
                        prevPointOfSail = pointOfSail;
                    } else if (pointOfSail == PointOfSail.JIBING) {
                        if (leftSide) {
                            direction = polarDiagram.optimalDirectionsDownwind()[1];
+                            layline = polarDiagram.optimalDirectionsDownwind()[0].reverse();
                        } else {
                            direction = polarDiagram.optimalDirectionsDownwind()[0];
+                            layline = polarDiagram.optimalDirectionsDownwind()[1].reverse();
                        }
                        prevPointOfSail = pointOfSail;
                    } else {
-                        direction = bearTarget;                                                
+                        direction = bearTarget;
+                        layline = null;
                    }
                    SpeedWithBearing currSpeed;
                    if ((pointOfSail != PointOfSail.REACHING) || !polarDiagram.hasCurrent()) {
@@ -181,6 +182,19 @@ public class PathGenerator1Turner360 extends PathGeneratorBase {
                    }
                    nextTime = new MillisecondsTimePoint(currentTime.asMillis() + timeStep);
                    Position nextPosition = currSpeed.travelTo(currentPosition, currentTime, nextTime);
+                    // scale step at layline            
+                    if (layline != null) {
+                        Bearing nextBearTarget = nextPosition.getBearingGreatCircle(posEnd);
+                        Util.Pair<PointOfSail, BoatDirection> nextPointOfSailAndReachingSide = polarDiagram.getPointOfSail(nextBearTarget);
+                        PointOfSail nextPointOfSail = nextPointOfSailAndReachingSide.getA();
+                        if (nextPointOfSail != pointOfSail) {
+                            Position tmpPosition = nextPosition.projectToLineThrough(posEnd, layline);
+                            long scaledTimeStep = Math.round(timeStep*currentPosition.getDistance(tmpPosition).getMeters() / currentPosition.getDistance(nextPosition).getMeters());
+                            nextTime = new MillisecondsTimePoint(currentTime.asMillis() + scaledTimeStep);
+                            nextPosition = currSpeed.travelTo(currentPosition, currentTime, nextTime);                        
+                        }
+                    }
+                    
                    newDistance = nextPosition.getDistance(posEnd).getMeters();
                    if (newDistance < minimumDistance) {
                        minimumDistance = newDistance;
@@ -190,14 +204,12 @@ public class PathGenerator1Turner360 extends PathGeneratorBase {
                    currentTime = nextTime;
                }                
                if (currentPosition.getDistance(posEnd).getMeters() < reachingTolerance * courseLength.getMeters()) {
-                    reachTime[step] = minimumDistance;
-                    targetFound = true;
+                    if (posStart.getDistance(currentPosition).getMeters() > posStart.getDistance(posEnd).getMeters()) {
+                        targetFound = true;
+                    }
                }
-                //if (minimumDistance < overallMinimumDistance) {
                if (targetFound&&(currentTime.before(minimumTime))) {
-                    //overallMinimumDistance = minimumDistance;
                    minimumTime = currentTime;
-                    //stepOfOverallMinimumDistance = step;
                    allminpath = path;
                }
                stepLeft++;
@@ -251,18 +263,12 @@ public class PathGenerator1Turner360 extends PathGeneratorBase {
                    currentTime = nextTime;
                }
                if (currentPosition.getDistance(posEnd).getMeters() < reachingTolerance * courseLength.getMeters()) {
-                    Bearing bearPath2End = currentPosition.getBearingGreatCircle(posEnd);
-                    double bearDiff = bearPath2End.getDegrees() - bearStart2End.getDegrees();
-                    reachTime[step] = minimumDistance * Math.signum(bearDiff);
                    if (posStart.getDistance(currentPosition).getMeters() > posStart.getDistance(posEnd).getMeters()) {
                        targetFound = true;
                    }
                }
-                //if (minimumDistance < overallMinimumDistance) {
                if (targetFound&&(currentTime.before(minimumTime))) {
-                    //overallMinimumDistance = minimumDistance;
                    minimumTime = currentTime;
-                    //stepOfOverallMinimumDistance = step;
                    allminpath = new LinkedList<TimedPositionWithSpeed>(path);
                }
                stepRight++;
@@ -34,7 +34,7 @@ public class PathGeneratorBase implements PathGenerator {
    }

    @Override
-    public Path getPath() throws SparsePolarDataException {
+    public Path getPath() throws SparseSimulationDataException {
        return null;
    }

@@ -51,7 +51,7 @@ public class PathGeneratorBase implements PathGenerator {
    }

    @Override
-    public Path getPathEvenTimed(long stepMilliseconds) throws SparsePolarDataException {
+    public Path getPathEvenTimed(long stepMilliseconds) throws SparseSimulationDataException {

        Path path = this.getPath();

@@ -60,7 +60,7 @@ public class PathGeneratorOpportunistEuclidian360 extends PathGeneratorBase {

    
    @Override
-    public Path getPath() {
+    public Path getPath() throws SparseSimulationDataException {
        this.algorithmStartTime = MillisecondsTimePoint.now();

        WindFieldGenerator wf = parameters.getWindField();
@@ -79,7 +79,7 @@ public class PathGeneratorOpportunistEuclidian360 extends PathGeneratorBase {

        BoatDirection prevDirection = BoatDirection.NONE;
        long turnLoss = polarDiagram.getTurnLoss(); // time lost when doing a turn
-        double fracFinishPhase = 0.075;
+        double fracFinishPhase = 0.05;

        TimePoint travelTimeLeft;
        TimePoint travelTimeRight;
@@ -167,7 +167,15 @@ public class PathGeneratorOpportunistEuclidian360 extends PathGeneratorBase {
                }
                // get boat speed at current position
                SpeedWithBearing boatSpeedLeft = polarDiagram.getSpeedAtBearing(bearLeft);
+                if (boatSpeedLeft.getKnots() == 0) {
+                    logger.severe("Travel Speed for NextDirection '" + "L" + "' is ZERO. This must NOT happen.");            
+                    throw new SparseSimulationDataException();
+                }
                SpeedWithBearing boatSpeedRight = polarDiagram.getSpeedAtBearing(bearRight);
+                if (boatSpeedRight.getKnots() == 0) {
+                    logger.severe("Travel Speed for NextDirection '" + "R" + "' is ZERO. This must NOT happen.");            
+                    throw new SparseSimulationDataException();
+                }
                logger.finest("left boat speed:" + boatSpeedLeft.getKnots() + " angle:" + boatSpeedLeft.getBearing().getDegrees()
                        + "  right boat speed:" + boatSpeedRight.getKnots() + " angle:" + boatSpeedRight.getBearing().getDegrees());

@@ -183,7 +191,7 @@ public class PathGeneratorOpportunistEuclidian360 extends PathGeneratorBase {
                    travelTimeRight = new MillisecondsTimePoint(nextTimeVal);
                }
                
-                // get next boat positions by travelling left and right
+                // get next boat positions by traveling left and right
                Position nextBoatPositionLeft = boatSpeedLeft.travelTo(currentPosition, currentTime, travelTimeLeft);
                Position nextBoatPositionRight = boatSpeedRight.travelTo(currentPosition, currentTime, travelTimeRight);
                // calculate distance to target left and right
@@ -267,7 +275,11 @@ public class PathGeneratorOpportunistEuclidian360 extends PathGeneratorBase {
                } else {
                    boatSpeedTarget = polarDiagram.getSpeedAtBearing(bearTarget);                    
                }
-                // get next boat positions by travelling left and right
+                if ((boatSpeedTarget.getKnots() == 0)&&(!polarDiagram.hasCurrent())) {
+                    logger.severe("Travel Speed for NextDirection '" + (reachingSide==BoatDirection.REACH_LEFT?"D":"E") + "' is ZERO. This must NOT happen.");            
+                    throw new SparseSimulationDataException();
+                }
+                // get next boat positions by traveling reach
                Position nextBoatPositionReach = boatSpeedTarget.travelTo(currentPosition, currentTime, travelTimeReach);
                path.add(new TimedPositionWithSpeedImpl(nextTime, nextBoatPositionReach, currentWind));
                currentPosition = nextBoatPositionReach;
@@ -288,11 +300,6 @@ public class PathGeneratorOpportunistEuclidian360 extends PathGeneratorBase {
            currentHeight = startPos.getDistance(endPos).getMeters() - posHeight.getDistance(startPos).getMeters();
        }
        
-        // remove last position, if already too close to target for finish-phase
-        if (currentHeight < startPos.getDistance(endPos).getMeters()*fracFinishPhase/2) {
-            path.remove(path.size()-1);
-        }
-        
        if (!this.isTimedOut()) {
            //
            // FinishPhase: get 1-turners to finalize course
@@ -310,11 +317,11 @@ public class PathGeneratorOpportunistEuclidian360 extends PathGeneratorBase {

            long finishTimeStep = Math.max(500, timeStep / 10);
            int finishStepsLeft = (int) Math.round(1.5*(path.get(path.size()-1).getTimePoint().asMillis() - path.get(0).getTimePoint().asMillis()) / (1-fracFinishPhase) * fracFinishPhase / finishTimeStep);
-            generator1Turner.setEvaluationParameters(true, currentPosition, endPos, leftTurningTime, finishTimeStep, finishStepsLeft, 0.05, this.upwindLeg);
+            generator1Turner.setEvaluationParameters(true, currentPosition, endPos, leftTurningTime, finishTimeStep, finishStepsLeft, 0.2, this.upwindLeg);
            Path leftPath = generator1Turner.getPath();

            int finishStepsRight = (int) Math.round(1.5*(path.get(path.size()-1).getTimePoint().asMillis() - path.get(0).getTimePoint().asMillis()) / (1-fracFinishPhase) * fracFinishPhase / finishTimeStep);
-            generator1Turner.setEvaluationParameters(false, currentPosition, endPos, rightTurningTime, finishTimeStep, finishStepsRight, 0.05, this.upwindLeg);
+            generator1Turner.setEvaluationParameters(false, currentPosition, endPos, rightTurningTime, finishTimeStep, finishStepsRight, 0.2, this.upwindLeg);
            Path rightPath = generator1Turner.getPath();

            if ((leftPath.getPathPoints() != null) && (rightPath.getPathPoints() != null)) {
@@ -109,7 +109,7 @@ public class PathGeneratorTreeGrow360 extends PathGeneratorBase {
    // default: L - left, R - right
    // extended: M - wide left, S - wide right
    TimedPosition getStep(TimedPosition pos, Wind posWind, Position posEnd, long timeStep, long turnLoss, boolean sameBaseDirection,
-            char nextDirection) throws SparsePolarDataException {
+            char nextDirection) throws SparseSimulationDataException {

        TimePoint curTime = pos.getTimePoint();
        Position curPosition = pos.getPosition();
@@ -152,9 +152,14 @@ public class PathGeneratorTreeGrow360 extends PathGeneratorBase {
            if (travelSpeed == null) {
                logger.severe("Travel Speed for NextDirection '" + nextDirection + "' is NULL. This must NOT happen.");
            }
-            throw new SparsePolarDataException();
+            throw new SparseSimulationDataException();
        }     

+        if ((travelSpeed.getKnots() == 0)&&(!polarDiagram.hasCurrent())) {
+            logger.severe("Travel Speed for NextDirection '" + nextDirection + "' is ZERO. This must NOT happen.");            
+            throw new SparseSimulationDataException();
+        }
+        
        TimePoint travelTime;
        TimePoint nextTime = new MillisecondsTimePoint(curTime.asMillis() + timeStep);
        if (sameBaseDirection) {
@@ -201,7 +206,7 @@ public class PathGeneratorTreeGrow360 extends PathGeneratorBase {
    
    // get path candidate measuring height towards (local, current-apparent) wind
    PathCandidate getPathCandWind(PathCandidate path, char nextDirection, long timeStep, long turnLoss,
-            Position posStart, Position posEnd, double tgtHeight) throws SparsePolarDataException {
+            Position posStart, Position posEnd, double tgtHeight) throws SparseSimulationDataException {

        char prevDirection = path.path.charAt(path.path.length() - 1);
        boolean sameBaseDirection = this.isSameDirection(prevDirection, nextDirection);
@@ -267,7 +272,7 @@ public class PathGeneratorTreeGrow360 extends PathGeneratorBase {

    // generate path candidates based on bearing to target
    List<PathCandidate> getPathCandsBeatWind(PathCandidate path, long timeStep, long turnLoss, Position posStart,
-            Position posEnd, double tgtHeight) throws SparsePolarDataException {
+            Position posEnd, double tgtHeight) throws SparseSimulationDataException {
        
        // determine bearing of target
        Bearing bearTarget = path.pos.getPosition().getBearingGreatCircle(posEnd);
@@ -399,7 +404,7 @@ public class PathGeneratorTreeGrow360 extends PathGeneratorBase {
    }

    Util.Pair<List<PathCandidate>, List<PathCandidate>> generateCandidate(List<PathCandidate> oldPaths, long timeStep,
-            long turnLoss, Position posStart, Position posMiddle, Position posEnd, double tgtHeight) throws SparsePolarDataException {
+            long turnLoss, Position posStart, Position posMiddle, Position posEnd, double tgtHeight) throws SparseSimulationDataException {

        List<PathCandidate> newPathCands;
        List<PathCandidate> leftPaths = new ArrayList<PathCandidate>();
@@ -585,7 +590,7 @@ public class PathGeneratorTreeGrow360 extends PathGeneratorBase {
    }

    @Override
-    public Path getPath() throws SparsePolarDataException {
+    public Path getPath() throws SparseSimulationDataException {
        this.algorithmStartTime = MillisecondsTimePoint.now();
        
        WindFieldGenerator wf = this.parameters.getWindField();
@@ -140,9 +140,6 @@ public class PathImpl implements Path, Serializable {
                TimedPositionWithSpeed p1 = this.pathPoints.get(idx - 1);
                TimedPositionWithSpeed p2 = this.pathPoints.get(idx);
                Distance dist = p1.getPosition().getDistance(p2.getPosition());
-                // long nextTime = (double)nextTimePoint.asMillis();
-                // System.out.println(""+(nextTimePoint.asMillis() -
-                // p1.getTimePoint().asMillis())+" - "+(p2.getTimePoint().asMillis() - p1.getTimePoint().asMillis()));
                double scale1 = nextTimePoint.asMillis() - p1.getTimePoint().asMillis();
                double scale2 = p2.getTimePoint().asMillis() - p1.getTimePoint().asMillis();
                Position nextPosition = p1.getPosition().translateGreatCircle(
@@ -168,32 +165,42 @@ public class PathImpl implements Path, Serializable {
                double scaleDist = 0.01 * nextPoint.getPosition().getDistance(prevPoint.getPosition())
                        .getMeters();

-                // evaluate collected points to potentially find turn/corner
-                double maxDist = 0;
-                TimedPositionWithSpeed maxPoint = null;
+                // evaluate collected points to potentially find turn/corner (up to two)
+                double prevSide = 0;
+                int maxCnt = 0;
+                ArrayList<TimedPositionWithSpeed> maxPoint = new ArrayList<TimedPositionWithSpeed>();
+                maxPoint.add(path.get(0));
+                ArrayList<Double> maxDist = new ArrayList<Double>();
+                maxDist.add(new Double(0));
                Bearing nextBear = prevPoint.getPosition().getBearingGreatCircle(nextPoint.getPosition());
                for (int jdx = 0; jdx < points.size(); jdx++) {

                    Position pcur = points.get(jdx).getPosition();
                    Position ptmp = pcur.projectToLineThrough(prevPoint.getPosition(), nextBear);
-                    double lineDist = ptmp.getDistance(pcur).getMeters();
-                    if (lineDist > maxDist) {
-                        maxPoint = points.get(jdx);
-                        maxDist = lineDist;
+                    double side = Math.signum(nextBear.getDifferenceTo(prevPoint.getPosition().getBearingGreatCircle(pcur)).getDegrees());
+                    boolean sideChange = (prevSide != 0)&&(side != prevSide);
+                    double lineDist = Math.round(ptmp.getDistance(pcur).getMeters()*1000.0)/1000.0;
+                    if (sideChange) {
+                        maxCnt++;
+                        maxDist.add(new Double(0));
+                        maxPoint.add(path.get(0));
                    }
-
+                    if (lineDist > maxDist.get(maxCnt)) {
+                        maxPoint.set(maxCnt, points.get(jdx));
+                        maxDist.set(maxCnt, lineDist);
+                    }
+                    prevSide = side;
                }
-
-                if (maxDist > scaleDist) {
-                    // add intermediate corner point
-                    SpeedWithBearing maxWind = null;
-                    if (this.windField != null) {
-                        maxWind = this.windField.getWind(new TimedPositionImpl(maxPoint.getTimePoint(), maxPoint
-                                .getPosition()));
-                        maxPoint = new TimedPositionWithSpeedImpl(maxPoint.getTimePoint(), maxPoint.getPosition(),
-                                maxWind);
+                for(int cnt=0; cnt<=maxCnt; cnt++) {
+                    if (maxDist.get(cnt) > scaleDist) {
+                        // add intermediate corner point
+                        SpeedWithBearing maxWind = null;
+                        if (this.windField != null) {
+                            maxWind = this.windField.getWind(new TimedPositionImpl(maxPoint.get(cnt).getTimePoint(), maxPoint.get(cnt).getPosition()));
+                            maxPoint.set(cnt, new TimedPositionWithSpeedImpl(maxPoint.get(cnt).getTimePoint(), maxPoint.get(cnt).getPosition(), maxWind));
+                        }
+                        path.add(maxPoint.get(cnt));
                    }
-                    path.add(maxPoint);
                }

                // add next even timed point
@@ -25,7 +25,7 @@ public class PolarDiagramGPS extends PolarDiagramBase {
    private final PolarDataService polarData;
    private double avgSpeed;

-    public PolarDiagramGPS(BoatClass boatClass, PolarDataService polarData) throws SparsePolarDataException {
+    public PolarDiagramGPS(BoatClass boatClass, PolarDataService polarData) throws SparseSimulationDataException {
        this.boatClass = boatClass;
        this.polarData = polarData;

@@ -102,7 +102,7 @@ public class PolarDiagramGPS extends PolarDiagramBase {
        }

        if ((beatAngles.size() <= 1)||(beatSpeed.size() <= 1)||(jibeAngles.size() <= 1)||(jibeSpeed.size() <= 1)) {
-            throw new SparsePolarDataException();
+            throw new SparseSimulationDataException();
        }
        
        NavigableMap<Speed, NavigableMap<Bearing, Speed>> mapSpeedTable = new TreeMap<Speed, NavigableMap<Bearing, Speed>>();
@@ -40,7 +40,7 @@ public class SimulatorImpl implements Simulator {
    }

    @Override
-    public Path getPath(PathType pathType) throws SparsePolarDataException {
+    public Path getPath(PathType pathType) throws SparseSimulationDataException {
        PathGeneratorTreeGrow360 genTreeGrow;
        PathGeneratorOpportunistEuclidian360 genOpportunistic;
        Path path = null;
@@ -1,15 +0,0 @@
-package com.sap.sailing.simulator.impl;
-
-public class SparsePolarDataException extends Exception {
-
-    private static final long serialVersionUID = 4134116458606258315L;
-
-    public SparsePolarDataException() {
-        super("Not enough polar data to represent beat/jibe angles/speeds for simulation.");
-    }
-
-    public SparsePolarDataException(String string) {
-        super(string);
-    }
-
-}
@@ -0,0 +1,15 @@
+package com.sap.sailing.simulator.impl;
+
+public class SparseSimulationDataException extends Exception {
+
+    private static final long serialVersionUID = 4134116458606258315L;
+
+    public SparseSimulationDataException() {
+        super("Not enough simulation data available (sparse wind data or sparse polar data for beat/jibe angles/speeds).");
+    }
+
+    public SparseSimulationDataException(String string) {
+        super(string);
+    }
+
+}