Package org.apache.lucene.geo
Class GeoEncodingUtils
java.lang.Object
org.apache.lucene.geo.GeoEncodingUtils
reusable geopoint encoding methods
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic class
A predicate that checks whether a given point is within a component2D geometry.static class
A predicate that checks whether a given point is within a distance of another point.private static class
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final short
number of bits used for quantizing latitude and longitude valuesprivate static final double
private static final double
private static final double
private static final double
static final int
static final int
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionprivate static int
computeShift
(long a, long b) Compute the minimum shift value so that(b>>>shift)-(a>>>shift)
is less thatARITY
.Create a predicate that checks whether points are within a geometry.createDistancePredicate
(double lat, double lon, double radiusMeters) Create a predicate that checks whether points are within a distance of a given point.private static GeoEncodingUtils.Grid
createSubBoxes
(double shapeMinLat, double shapeMaxLat, double shapeMinLon, double shapeMaxLon, Function<Rectangle, PointValues.Relation> boxToRelation) static double
decodeLatitude
(byte[] src, int offset) Turns quantized value from byte array back into a double.static double
decodeLatitude
(int encoded) Turns quantized value fromencodeLatitude(double)
back into a double.static double
decodeLongitude
(byte[] src, int offset) Turns quantized value from byte array back into a double.static double
decodeLongitude
(int encoded) Turns quantized value fromencodeLongitude(double)
back into a double.static int
encodeLatitude
(double latitude) Quantizes double (64 bit) latitude into 32 bits (rounding down: in the direction of -90)static int
encodeLatitudeCeil
(double latitude) Quantizes double (64 bit) latitude into 32 bits (rounding up: in the direction of +90)static int
encodeLongitude
(double longitude) Quantizes double (64 bit) longitude into 32 bits (rounding down: in the direction of -180)static int
encodeLongitudeCeil
(double longitude) Quantizes double (64 bit) longitude into 32 bits (rounding up: in the direction of +180)
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Field Details
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BITS
public static final short BITSnumber of bits used for quantizing latitude and longitude values- See Also:
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LAT_SCALE
private static final double LAT_SCALE- See Also:
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LAT_DECODE
private static final double LAT_DECODE- See Also:
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LON_SCALE
private static final double LON_SCALE- See Also:
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LON_DECODE
private static final double LON_DECODE- See Also:
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MIN_LON_ENCODED
public static final int MIN_LON_ENCODED -
MAX_LON_ENCODED
public static final int MAX_LON_ENCODED
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Constructor Details
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GeoEncodingUtils
private GeoEncodingUtils()
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Method Details
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encodeLatitude
public static int encodeLatitude(double latitude) Quantizes double (64 bit) latitude into 32 bits (rounding down: in the direction of -90)- Parameters:
latitude
- latitude value: must be within standard +/-90 coordinate bounds.- Returns:
- encoded value as a 32-bit
int
- Throws:
IllegalArgumentException
- if latitude is out of bounds
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encodeLatitudeCeil
public static int encodeLatitudeCeil(double latitude) Quantizes double (64 bit) latitude into 32 bits (rounding up: in the direction of +90)- Parameters:
latitude
- latitude value: must be within standard +/-90 coordinate bounds.- Returns:
- encoded value as a 32-bit
int
- Throws:
IllegalArgumentException
- if latitude is out of bounds
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encodeLongitude
public static int encodeLongitude(double longitude) Quantizes double (64 bit) longitude into 32 bits (rounding down: in the direction of -180)- Parameters:
longitude
- longitude value: must be within standard +/-180 coordinate bounds.- Returns:
- encoded value as a 32-bit
int
- Throws:
IllegalArgumentException
- if longitude is out of bounds
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encodeLongitudeCeil
public static int encodeLongitudeCeil(double longitude) Quantizes double (64 bit) longitude into 32 bits (rounding up: in the direction of +180)- Parameters:
longitude
- longitude value: must be within standard +/-180 coordinate bounds.- Returns:
- encoded value as a 32-bit
int
- Throws:
IllegalArgumentException
- if longitude is out of bounds
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decodeLatitude
public static double decodeLatitude(int encoded) Turns quantized value fromencodeLatitude(double)
back into a double.- Parameters:
encoded
- encoded value: 32-bit quantized value.- Returns:
- decoded latitude value.
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decodeLatitude
public static double decodeLatitude(byte[] src, int offset) Turns quantized value from byte array back into a double.- Parameters:
src
- byte array containing 4 bytes to decode atoffset
offset
- offset intosrc
to decode from.- Returns:
- decoded latitude value.
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decodeLongitude
public static double decodeLongitude(int encoded) Turns quantized value fromencodeLongitude(double)
back into a double.- Parameters:
encoded
- encoded value: 32-bit quantized value.- Returns:
- decoded longitude value.
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decodeLongitude
public static double decodeLongitude(byte[] src, int offset) Turns quantized value from byte array back into a double.- Parameters:
src
- byte array containing 4 bytes to decode atoffset
offset
- offset intosrc
to decode from.- Returns:
- decoded longitude value.
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createDistancePredicate
public static GeoEncodingUtils.DistancePredicate createDistancePredicate(double lat, double lon, double radiusMeters) Create a predicate that checks whether points are within a distance of a given point. It works by computing the bounding box around the circle that is defined by the given points/distance and splitting it into between 1024 and 4096 smaller boxes (4096*0.75^2=2304 on average). Then for each sub box, it computes the relation between this box and the distance query. Finally at search time, it first computes the sub box that the point belongs to, most of the time, no distance computation will need to be performed since all points from the sub box will either be in or out of the circle. -
createComponentPredicate
Create a predicate that checks whether points are within a geometry. It works the same way ascreateDistancePredicate(double, double, double)
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createSubBoxes
private static GeoEncodingUtils.Grid createSubBoxes(double shapeMinLat, double shapeMaxLat, double shapeMinLon, double shapeMaxLon, Function<Rectangle, PointValues.Relation> boxToRelation) -
computeShift
private static int computeShift(long a, long b) Compute the minimum shift value so that(b>>>shift)-(a>>>shift)
is less thatARITY
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