virtual Vector getNearestCenter(const Vector & coord, double * dist = NULL);
virtual Vector getNearestMiddle(const Vector & coord, double * dist = NULL);
virtual Vector getNearestDist(double distance, const Vector & coord, double * dist = NULL);
virtual Vector getNearestDist(double distance, bool startp);
virtual Vector getNearestCenter(const Vector & coord, double * dist = NULL);
virtual Vector getNearestMiddle(const Vector & coord, double * dist = NULL);
virtual Vector getNearestDist(double distance, const Vector & coord, double * dist = NULL);
virtual Vector getNearestDist(double distance, bool startp);