Program: 189540
Project: 189540
Buggy source:
public static void convertToGroundBelief(MultivariateGaussian belief,PathEdge edge){
  Preconditions.checkArgument(belief.getInputDimensionality() == 2 || belief.getInputDimensionality() == 4);
  if (belief.getInputDimensionality() == 4)   return;
  Preconditions.checkArgument(!edge.isEmptyEdge());
  final Entry<LineSegment,Double> segmentDist=getSegmentAndDistanceToStart(edge,belief.getMean().getElement(0));
  final Entry<Matrix,Vector> projPair=StandardRoadTrackingFilter.posVelProjectionPair(segmentDist.getKey(),segmentDist.getValue());
  final double totalPathDistanceToEdge=Math.abs(edge.getDistToStartOfEdge()) + edge.getInferredEdge().getLength();
  final Vector positiveMean;
  if (belief.getMean().getElement(0) < 0d) {
    final Vector posMeanTmp=belief.getMean().clone();
    final double distance=totalPathDistanceToEdge + belief.getMean().getElement(0);
    posMeanTmp.setElement(0,distance);
    positiveMean=posMeanTmp;
  }
 else {
    positiveMean=belief.getMean();
  }
  if (positiveMean.getElement(0) > totalPathDistanceToEdge) {
    positiveMean.setElement(0,totalPathDistanceToEdge);
  }
 else   if (positiveMean.getElement(0) < Math.abs(edge.getDistToStartOfEdge())) {
    positiveMean.setElement(0,Math.abs(edge.getDistToStartOfEdge()));
  }
  final Matrix C=belief.getCovariance();
  final Vector projMean=projPair.getKey().times(positiveMean).plus(projPair.getValue());
  final Matrix projCov=projPair.getKey().times(C).times(projPair.getKey().transpose());
  belief.setMean(projMean);
  belief.setCovariance(projCov);
}

Fixed version (ground truth):
public static void convertToGroundBelief(MultivariateGaussian belief,PathEdge edge){
  Preconditions.checkArgument(belief.getInputDimensionality() == 2 || belief.getInputDimensionality() == 4);
  if (belief.getInputDimensionality() == 4)   return;
  Preconditions.checkArgument(!edge.isEmptyEdge());
  final Entry<LineSegment,Double> segmentDist=getSegmentAndDistanceToStart(edge,belief.getMean().getElement(0));
  final double absTotalPathDistanceToStartOfSegment=Math.abs(segmentDist.getValue());
  final double absTotalPathDistanceToEndOfSegment=absTotalPathDistanceToStartOfSegment + GeoUtils.getAngleDegreesInMeters(segmentDist.getKey().getLength());
  final Entry<Matrix,Vector> projPair=StandardRoadTrackingFilter.posVelProjectionPair(segmentDist.getKey(),absTotalPathDistanceToStartOfSegment);
  final Vector positiveMean;
  if (belief.getMean().getElement(0) < 0d) {
    final Vector posMeanTmp=belief.getMean().clone();
    final double distance=Math.abs(edge.getDistToStartOfEdge()) + edge.getInferredEdge().getLength() + belief.getMean().getElement(0);
    posMeanTmp.setElement(0,distance);
    positiveMean=posMeanTmp;
  }
 else {
    positiveMean=belief.getMean();
  }
  if (positiveMean.getElement(0) > absTotalPathDistanceToEndOfSegment) {
    positiveMean.setElement(0,absTotalPathDistanceToEndOfSegment);
  }
 else   if (positiveMean.getElement(0) < absTotalPathDistanceToStartOfSegment) {
    positiveMean.setElement(0,absTotalPathDistanceToStartOfSegment);
  }
  final Matrix C=belief.getCovariance();
  final Vector projMean=projPair.getKey().times(positiveMean).plus(projPair.getValue());
  final Matrix projCov=projPair.getKey().times(C).times(projPair.getKey().transpose());
  belief.setMean(projMean);
  belief.setCovariance(projCov);
}