## org.apache.lucene.spatial.prefix.tree
Class QuadPrefixTree

    java.lang.Object
      org.apache.lucene.spatial.prefix.tree.SpatialPrefixTree
          org.apache.lucene.spatial.prefix.tree.QuadPrefixTree

    public class QuadPrefixTree

extends SpatialPrefixTree

A `SpatialPrefixTree` which uses a quad tree in which an indexed term will be generated for each cell, 'A', 'B', 'C', 'D'.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary
`static class` `QuadPrefixTree.Factory` Factory for creating `QuadPrefixTree` instances with useful defaults

Field Summary
`static int` `DEFAULT_MAX_LEVELS`
`double` `gridH`
`static int` `MAX_LEVELS_POSSIBLE`

Fields inherited from class org.apache.lucene.spatial.prefix.tree.SpatialPrefixTree
`ctx, maxLevels, UTF8`

Constructor Summary
`QuadPrefixTree(com.spatial4j.core.context.SpatialContext ctx)`
`QuadPrefixTree(com.spatial4j.core.context.SpatialContext ctx, int maxLevels)`
`QuadPrefixTree(com.spatial4j.core.context.SpatialContext ctx, com.spatial4j.core.shape.Rectangle bounds, 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).
`void` `printInfo(PrintStream out)`

Methods inherited from class org.apache.lucene.spatial.prefix.tree.SpatialPrefixTree
`cellsToTokenStrings, getCell, getCells, getCells, getDistanceForLevel, getMaxLevels, getSpatialContext, getWorldCell, toString`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

Field Detail

### MAX_LEVELS_POSSIBLE

    public static final int MAX_LEVELS_POSSIBLE

See Also:
  Constant Field Values

### DEFAULT_MAX_LEVELS

    public static final int DEFAULT_MAX_LEVELS

See Also:
  Constant Field Values

### gridH

    public final double gridH

Constructor Detail

### QuadPrefixTree

    public QuadPrefixTree(com.spatial4j.core.context.SpatialContext ctx,
                          com.spatial4j.core.shape.Rectangle bounds,
                          int maxLevels)

### QuadPrefixTree

    public QuadPrefixTree(com.spatial4j.core.context.SpatialContext ctx)

### QuadPrefixTree

    public QuadPrefixTree(com.spatial4j.core.context.SpatialContext ctx,
                          int maxLevels)

Method Detail

### printInfo

    public void printInfo(PrintStream out)

### 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`

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