Class GeoUtils


  • public final class GeoUtils
    extends Object
    Basic reusable geo-spatial utility methods
    WARNING: This API is experimental and might change in incompatible ways in the next release.
    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  GeoUtils.WindingOrder
      used to define the orientation of 3 points -1 = Clockwise 0 = Colinear 1 = Counter-clockwise
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static void checkLatitude​(double latitude)
      validates latitude value is within standard +/-90 coordinate bounds
      static void checkLongitude​(double longitude)
      validates longitude value is within standard +/-180 coordinate bounds
      static double distanceQuerySortKey​(double radius)
      binary search to find the exact sortKey needed to match the specified radius any sort key lte this is a query match.
      static boolean lineCrossesLine​(double a1x, double a1y, double b1x, double b1y, double a2x, double a2y, double b2x, double b2y)
      uses orient method to compute whether two line segments cross
      static boolean lineCrossesLineWithBoundary​(double a1x, double a1y, double b1x, double b1y, double a2x, double a2y, double b2x, double b2y)
      uses orient method to compute whether two line segments cross; boundaries included - returning true for lines that terminate on each other.
      static int orient​(double ax, double ay, double bx, double by, double cx, double cy)
      Returns a positive value if points a, b, and c are arranged in counter-clockwise order, negative value if clockwise, zero if collinear.
      static PointValues.Relation relate​(double minLat, double maxLat, double minLon, double maxLon, double lat, double lon, double distanceSortKey, double axisLat)
      Compute the relation between the provided box and distance query.
      static double sloppySin​(double a)
      Returns the trigonometric sine of an angle converted as a cos operation.
    • Field Detail

      • MIN_LON_INCL

        public static final double MIN_LON_INCL
        Minimum longitude value.
        See Also:
        Constant Field Values
      • MAX_LON_INCL

        public static final double MAX_LON_INCL
        Maximum longitude value.
        See Also:
        Constant Field Values
      • MIN_LAT_INCL

        public static final double MIN_LAT_INCL
        Minimum latitude value.
        See Also:
        Constant Field Values
      • MAX_LAT_INCL

        public static final double MAX_LAT_INCL
        Maximum latitude value.
        See Also:
        Constant Field Values
      • MIN_LON_RADIANS

        public static final double MIN_LON_RADIANS
        min longitude value in radians
        See Also:
        Constant Field Values
      • MIN_LAT_RADIANS

        public static final double MIN_LAT_RADIANS
        min latitude value in radians
        See Also:
        Constant Field Values
      • MAX_LON_RADIANS

        public static final double MAX_LON_RADIANS
        max longitude value in radians
        See Also:
        Constant Field Values
      • MAX_LAT_RADIANS

        public static final double MAX_LAT_RADIANS
        max latitude value in radians
        See Also:
        Constant Field Values
      • EARTH_MEAN_RADIUS_METERS

        public static final double EARTH_MEAN_RADIUS_METERS
        mean earth axis in meters
        See Also:
        Constant Field Values
    • Method Detail

      • checkLatitude

        public static void checkLatitude​(double latitude)
        validates latitude value is within standard +/-90 coordinate bounds
      • checkLongitude

        public static void checkLongitude​(double longitude)
        validates longitude value is within standard +/-180 coordinate bounds
      • sloppySin

        public static double sloppySin​(double a)
        Returns the trigonometric sine of an angle converted as a cos operation.

        Note that this is not quite right... e.g. sin(0) != 0

        Special cases:

        • If the argument is NaN or an infinity, then the result is NaN.
        Parameters:
        a - an angle, in radians.
        Returns:
        the sine of the argument.
        See Also:
        Math.sin(double)
      • distanceQuerySortKey

        public static double distanceQuerySortKey​(double radius)
        binary search to find the exact sortKey needed to match the specified radius any sort key lte this is a query match.
      • relate

        public static PointValues.Relation relate​(double minLat,
                                                  double maxLat,
                                                  double minLon,
                                                  double maxLon,
                                                  double lat,
                                                  double lon,
                                                  double distanceSortKey,
                                                  double axisLat)
        Compute the relation between the provided box and distance query. This only works for boxes that do not cross the dateline.
      • orient

        public static int orient​(double ax,
                                 double ay,
                                 double bx,
                                 double by,
                                 double cx,
                                 double cy)
        Returns a positive value if points a, b, and c are arranged in counter-clockwise order, negative value if clockwise, zero if collinear.
      • lineCrossesLine

        public static boolean lineCrossesLine​(double a1x,
                                              double a1y,
                                              double b1x,
                                              double b1y,
                                              double a2x,
                                              double a2y,
                                              double b2x,
                                              double b2y)
        uses orient method to compute whether two line segments cross
      • lineCrossesLineWithBoundary

        public static boolean lineCrossesLineWithBoundary​(double a1x,
                                                          double a1y,
                                                          double b1x,
                                                          double b1y,
                                                          double a2x,
                                                          double a2y,
                                                          double b2x,
                                                          double b2y)
        uses orient method to compute whether two line segments cross; boundaries included - returning true for lines that terminate on each other. e.g., (plus sign) + == true, and (capital 't') T == true Use lineCrossesLine(double, double, double, double, double, double, double, double) to exclude lines that terminate on each other from the truth table