Package org.apache.lucene.geo

Class GeoUtils

java.lang.Object
org.apache.lucene.geo.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 enum 
    GeoUtils.WindingOrder
    used to define the orientation of 3 points -1 = Clockwise 0 = Colinear 1 = Counter-clockwise

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final double
    EARTH_MEAN_RADIUS_METERS
    mean earth axis in meters
    static final double
    MAX_LAT_INCL
    Maximum latitude value.
    static final double
    MAX_LAT_RADIANS
    max latitude value in radians
    static final double
    MAX_LON_INCL
    Maximum longitude value.
    static final double
    MAX_LON_RADIANS
    max longitude value in radians
    static final double
    MIN_LAT_INCL
    Minimum latitude value.
    static final double
    MIN_LAT_RADIANS
    min latitude value in radians
    static final double
    MIN_LON_INCL
    Minimum longitude value.
    static final double
    MIN_LON_RADIANS
    min longitude value in radians

  • Method Summary

    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 boolean
    lineOverlapLine(double a1x, double a1y, double b1x, double b1y, double a2x, double a2y, double b2x, double b2y)
    uses orient method to compute whether two line overlap 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.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • MIN_LON_INCL

      public static final double MIN_LON_INCL
      Minimum longitude value.
      See Also:

    • MAX_LON_INCL

      public static final double MAX_LON_INCL
      Maximum longitude value.
      See Also:

    • MIN_LAT_INCL

      public static final double MIN_LAT_INCL
      Minimum latitude value.
      See Also:

    • MAX_LAT_INCL

      public static final double MAX_LAT_INCL
      Maximum latitude value.
      See Also:

    • MIN_LON_RADIANS

      public static final double MIN_LON_RADIANS
      min longitude value in radians

    • MIN_LAT_RADIANS

      public static final double MIN_LAT_RADIANS
      min latitude value in radians

    • MAX_LON_RADIANS

      public static final double MAX_LON_RADIANS
      max longitude value in radians

    • MAX_LAT_RADIANS

      public static final double MAX_LAT_RADIANS
      max latitude value in radians

    • EARTH_MEAN_RADIUS_METERS

      public static final double EARTH_MEAN_RADIUS_METERS
      mean earth axis in meters
      See Also:

  • Method Details

    • 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:

    • 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

    • lineOverlapLine

      public static boolean lineOverlapLine(double a1x, double a1y, double b1x, double b1y, double a2x, double a2y, double b2x, double b2y)
      uses orient method to compute whether two line overlap each other

    • 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