Package org.elasticsearch.common.geo

Class GeoHashUtils

java.lang.Object

org.elasticsearch.common.geo.GeoHashUtils

public class GeoHashUtils
extends java.lang.Object

Utilities for converting to/from the GeoHash standard The geohash long format is represented as lon/lat (x/y) interleaved with the 4 least significant bits representing the level (1-12) [xyxy...xyxyllll] This differs from a morton encoded value which interleaves lat/lon (y/x).*

Field Summary

Fields

Modifier and Type	Field	Description
static short	BITS	number of bits used for quantizing latitude and longitude values
static int	PRECISION	maximum precision for geohash strings

Method Summary

Modifier and Type	Method	Description
static <E extends java.util.Collection<? super java.lang.String>> E	addNeighbors(java.lang.String geohash, int length, E neighbors)	Add all geohashes of the cells next to a given geohash to a list.
static <E extends java.util.Collection<? super java.lang.String>> E	addNeighbors(java.lang.String geohash, E neighbors)	Add all geohashes of the cells next to a given geohash to a list.
static org.apache.lucene.geo.Rectangle	bbox(java.lang.String geohash)	Computes the bounding box coordinates from a given geohash
static double	decodeLatitude(long hash)	decode latitude value from morton encoded geo point
static double	decodeLatitude(java.lang.String geohash)	returns the latitude value from the string based geohash
static double	decodeLongitude(long hash)	decode longitude value from morton encoded geo point
static double	decodeLongitude(java.lang.String geohash)	returns the latitude value from the string based geohash
static long	encodeLatLon(double lat, double lon)	31 bit encoding utils *
static long	fromMorton(long morton, int level)	Convert from a morton encoded long from a geohash encoded long
static long	longEncode(double lon, double lat, int level)	Encode lon/lat to the geohash based long format (lon/lat interleaved, 4 least significant bits = level)
static long	longEncode(long geohash, int level)	Encode an existing geohash long to the provided precision
static long	mortonEncode(long geoHashLong)	Encode to a morton long value from a given geohash long value
static long	mortonEncode(java.lang.String hash)	Encode to a morton long value from a given geohash string
static java.lang.String	neighbor(java.lang.String geohash, int level, int dx, int dy)	Calculate the geohash of a neighbor of a geohash
static java.util.Collection<? extends java.lang.CharSequence>	neighbors(java.lang.String geohash)	Calculate all neighbors of a given geohash cell.
static java.lang.String	stringEncode(double lon, double lat)	Encode to a geohash string from full resolution longitude, latitude)
static java.lang.String	stringEncode(double lon, double lat, int level)	Encode to a level specific geohash string from full resolution longitude, latitude
static java.lang.String	stringEncode(long geoHashLong)	Encode to a geohash string from the geohash based long format
static java.lang.String	stringEncodeFromMortonLong(long hashedVal)	Encode to a full precision geohash string from a given morton encoded long value
static java.lang.String	stringEncodeFromMortonLong(long hashedVal, int level)	Encode to a geohash string at a given level from a morton long

Methods inherited from class java.lang.Object

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

Field Detail

PRECISION

public static final int PRECISION

maximum precision for geohash strings

See Also:

Constant Field Values

BITS

public static final short BITS

number of bits used for quantizing latitude and longitude values

See Also:

Constant Field Values

Method Detail

encodeLatLon

public static long encodeLatLon(double lat,
                                double lon)

31 bit encoding utils *

longEncode

public static final long longEncode(double lon,
                                    double lat,
                                    int level)

Encode lon/lat to the geohash based long format (lon/lat interleaved, 4 least significant bits = level)

longEncode

public static long longEncode(long geohash,
                              int level)

Encode an existing geohash long to the provided precision

fromMorton

public static long fromMorton(long morton,
                              int level)

Convert from a morton encoded long from a geohash encoded long

stringEncode

public static final java.lang.String stringEncode(long geoHashLong)

Encode to a geohash string from the geohash based long format

stringEncode

public static final java.lang.String stringEncode(double lon,
                                                  double lat)

Encode to a geohash string from full resolution longitude, latitude)

stringEncode

public static final java.lang.String stringEncode(double lon,
                                                  double lat,
                                                  int level)

Encode to a level specific geohash string from full resolution longitude, latitude

stringEncodeFromMortonLong

public static final java.lang.String stringEncodeFromMortonLong(long hashedVal)
                                                         throws java.lang.Exception

Encode to a full precision geohash string from a given morton encoded long value

Throws:

java.lang.Exception

stringEncodeFromMortonLong

public static final java.lang.String stringEncodeFromMortonLong(long hashedVal,
                                                                int level)

Encode to a geohash string at a given level from a morton long

mortonEncode

public static final long mortonEncode(java.lang.String hash)

Encode to a morton long value from a given geohash string

mortonEncode

public static final long mortonEncode(long geoHashLong)

Encode to a morton long value from a given geohash long value

bbox

public static org.apache.lucene.geo.Rectangle bbox(java.lang.String geohash)

Computes the bounding box coordinates from a given geohash

Parameters:

geohash - Geohash of the defined cell

Returns:

GeoRect rectangle defining the bounding box

neighbors

public static java.util.Collection<? extends java.lang.CharSequence> neighbors(java.lang.String geohash)

Calculate all neighbors of a given geohash cell.

Parameters:

geohash - Geohash of the defined cell

Returns:

geohashes of all neighbor cells

neighbor

public static final java.lang.String neighbor(java.lang.String geohash,
                                              int level,
                                              int dx,
                                              int dy)

Calculate the geohash of a neighbor of a geohash

Parameters:

geohash - the geohash of a cell

level - level of the geohash

dx - delta of the first grid coordinate (must be -1, 0 or +1)

dy - delta of the second grid coordinate (must be -1, 0 or +1)

Returns:

geohash of the defined cell

addNeighbors

public static final <E extends java.util.Collection<? super java.lang.String>> E addNeighbors(java.lang.String geohash,
                                                                                              E neighbors)

Add all geohashes of the cells next to a given geohash to a list.

Parameters:

geohash - Geohash of a specified cell

neighbors - list to add the neighbors to

Returns:

the given list

addNeighbors

public static final <E extends java.util.Collection<? super java.lang.String>> E addNeighbors(java.lang.String geohash,
                                                                                              int length,
                                                                                              E neighbors)

Add all geohashes of the cells next to a given geohash to a list.

Parameters:

geohash - Geohash of a specified cell

length - level of the given geohash

neighbors - list to add the neighbors to

Returns:

the given list

decodeLongitude

public static final double decodeLongitude(long hash)

decode longitude value from morton encoded geo point

decodeLatitude

public static final double decodeLatitude(long hash)

decode latitude value from morton encoded geo point

decodeLatitude

public static final double decodeLatitude(java.lang.String geohash)

returns the latitude value from the string based geohash

decodeLongitude

public static final double decodeLongitude(java.lang.String geohash)

returns the latitude value from the string based geohash