org.apache.lucene.spatial.prefix.tree
Class GeohashPrefixTree
java.lang.Object
org.apache.lucene.spatial.prefix.tree.SpatialPrefixTree
org.apache.lucene.spatial.prefix.tree.GeohashPrefixTree
public class GeohashPrefixTree
- extends SpatialPrefixTree
A SpatialPrefixTree
based on
Geohashes.
Uses GeohashUtils
to do all the geohash work.
- WARNING: This API is experimental and might change in incompatible ways in the next release.
Constructor Summary |
GeohashPrefixTree(com.spatial4j.core.context.SpatialContext ctx,
int maxLevels)
|
Method Summary |
Cell |
getCell(byte[] bytes,
int offset,
int len)
|
Cell |
getCell(com.spatial4j.core.shape.Point p,
int level)
Returns the cell containing point p at the specified level . |
Cell |
getCell(String token)
The cell for the specified token. |
int |
getLevelForDistance(double dist)
Returns the level of the largest grid in which its longest side is less
than or equal to the provided distance (in degrees). |
static int |
getMaxLevelsPossible()
Any more than this and there's no point (double lat & lon are the same). |
GeohashPrefixTree
public GeohashPrefixTree(com.spatial4j.core.context.SpatialContext ctx,
int maxLevels)
getMaxLevelsPossible
public static int getMaxLevelsPossible()
- Any more than this and there's no point (double lat & lon are the same).
getLevelForDistance
public int getLevelForDistance(double dist)
- Description copied from class:
SpatialPrefixTree
- Returns the level of the largest grid in which its longest side is less
than or equal to the provided distance (in degrees). Consequently
dist
acts as an error epsilon declaring the amount of detail needed in the
grid, such that you can get a grid with just the right amount of
precision.
- Specified by:
getLevelForDistance
in class SpatialPrefixTree
- Parameters:
dist
- >= 0
- Returns:
- level [1 to maxLevels]
getCell
public Cell getCell(com.spatial4j.core.shape.Point p,
int level)
- Description copied from class:
SpatialPrefixTree
- Returns the cell containing point
p
at the specified level
.
- Overrides:
getCell
in class SpatialPrefixTree
getCell
public Cell getCell(String token)
- Description copied from class:
SpatialPrefixTree
- The cell for the specified token. The empty string should be equal to
SpatialPrefixTree.getWorldCell()
.
Precondition: Never called when token length > maxLevel.
- Specified by:
getCell
in class SpatialPrefixTree
getCell
public Cell getCell(byte[] bytes,
int offset,
int len)
- Specified by:
getCell
in class SpatialPrefixTree
Copyright © 2000-2013 Apache Software Foundation. All Rights Reserved.