Module org.apache.lucene.core

Package org.apache.lucene.document

Class FloatRange

java.lang.Object

org.apache.lucene.document.Field

org.apache.lucene.document.FloatRange

All Implemented Interfaces:

IndexableField

public class FloatRange
extends Field

An indexed Float Range field.

This field indexes dimensional ranges defined as min/max pairs. It supports up to a maximum of 4 dimensions (indexed as 8 numeric values). With 1 dimension representing a single float range, 2 dimensions representing a bounding box, 3 dimensions a bounding cube, and 4 dimensions a tesseract.

Multiple values for the same field in one document is supported, and open ended ranges can be defined using Float.NEGATIVE_INFINITY and Float.POSITIVE_INFINITY.

This field defines the following static factory methods for common search operations over float ranges:

• newIntersectsQuery() matches ranges that intersect the defined search range.
• newWithinQuery() matches ranges that are within the defined search range.
• newContainsQuery() matches ranges that contain the defined search range.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.document.Field

Field.Store

Field Summary

Fields

Modifier and Type	Field	Description
static final int	BYTES	stores float values so number of bytes is 4

Fields inherited from class org.apache.lucene.document.Field

fieldsData, name, tokenStream, type

Constructor Summary

Constructors

Constructor	Description
FloatRange(String name, float[] min, float[] max)	Create a new FloatRange type, from min/max parallel arrays

Method Summary

Modifier and Type	Method	Description
private static void	checkArgs(float[] min, float[] max)	validate the arguments
(package private) static float	decodeMax(byte[] b, int dimension)	decodes the max value (for the defined dimension) from the encoded input byte array
(package private) static float	decodeMin(byte[] b, int dimension)	decodes the min value (for the defined dimension) from the encoded input byte array
(package private) static byte[]	encode(float[] min, float[] max)	Encodes the min, max ranges into a byte array
private static void	encode(float val, byte[] bytes, int offset)	encode the given value into the byte array at the defined offset
float	getMax(int dimension)	Get the max value for the given dimension
float	getMin(int dimension)	Get the min value for the given dimension
private static FieldType	getType(int dimensions)	set the field type
static Query	newContainsQuery(String field, float[] min, float[] max)	Create a query for matching indexed float ranges that contain the defined range.
static Query	newCrossesQuery(String field, float[] min, float[] max)	Create a query for matching indexed ranges that cross the defined range.
static Query	newIntersectsQuery(String field, float[] min, float[] max)	Create a query for matching indexed ranges that intersect the defined range.
private static Query	newRelationQuery(String field, float[] min, float[] max, RangeFieldQuery.QueryType relation)	helper method for creating the desired relational query
static Query	newWithinQuery(String field, float[] min, float[] max)	Create a query for matching indexed ranges that are within the defined range.
void	setRangeValues(float[] min, float[] max)	Changes the values of the field.
String	toString()	Prints a Field for human consumption.
private static String	toString(byte[] ranges, int dimension)	Returns the String representation for the range at the given dimension
(package private) static void	verifyAndEncode(float[] min, float[] max, byte[] bytes)	encode the ranges into a sortable byte array (Float.NaN not allowed)

Methods inherited from class org.apache.lucene.document.Field

binaryValue, fieldType, getCharSequenceValue, invertableType, name, numericValue, readerValue, setBytesValue, setBytesValue, setByteValue, setDoubleValue, setFloatValue, setIntValue, setLongValue, setReaderValue, setShortValue, setStringValue, setTokenStream, storedValue, stringValue, tokenStream, tokenStreamValue

Methods inherited from class java.lang.Object

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

Field Details

BYTES

public static final int BYTES

stores float values so number of bytes is 4

See Also:

• Constant Field Values

Constructor Details

FloatRange

public FloatRange(String name,
 float[] min,
 float[] max)

Create a new FloatRange type, from min/max parallel arrays

Parameters:

name - field name. must not be null.

min - range min values; each entry is the min value for the dimension

max - range max values; each entry is the max value for the dimension

Method Details

getType

private static FieldType getType(int dimensions)

set the field type

setRangeValues

public void setRangeValues(float[] min,
 float[] max)

Changes the values of the field.

Parameters:

min - array of min values. (accepts Float.NEGATIVE_INFINITY)

max - array of max values. (accepts Float.POSITIVE_INFINITY)

Throws:

IllegalArgumentException - if min or max is invalid

checkArgs

private static void checkArgs(float[] min,
 float[] max)

validate the arguments

encode

static byte[] encode(float[] min,
 float[] max)

Encodes the min, max ranges into a byte array

verifyAndEncode

static void verifyAndEncode(float[] min,
 float[] max,
 byte[] bytes)

encode the ranges into a sortable byte array (Float.NaN not allowed)

example for 4 dimensions (8 bytes per dimension value): minD1 ... minD4 | maxD1 ... maxD4

encode

private static void encode(float val,
 byte[] bytes,
 int offset)

encode the given value into the byte array at the defined offset

getMin

public float getMin(int dimension)

Get the min value for the given dimension

Parameters:

dimension - the dimension, always positive

Returns:

the decoded min value

getMax

public float getMax(int dimension)

Get the max value for the given dimension

Parameters:

dimension - the dimension, always positive

Returns:

the decoded max value

decodeMin

static float decodeMin(byte[] b,
 int dimension)

decodes the min value (for the defined dimension) from the encoded input byte array

decodeMax

static float decodeMax(byte[] b,
 int dimension)

decodes the max value (for the defined dimension) from the encoded input byte array

newIntersectsQuery

public static Query newIntersectsQuery(String field,
 float[] min,
 float[] max)

Create a query for matching indexed ranges that intersect the defined range.

Parameters:

field - field name. must not be null.

min - array of min values. (accepts Float.NEGATIVE_INFINITY)

max - array of max values. (accepts Float.MAX_VALUE)

Returns:

query for matching intersecting ranges (overlap, within, or contains)

Throws:

IllegalArgumentException - if field is null, min or max is invalid

newContainsQuery

public static Query newContainsQuery(String field,
 float[] min,
 float[] max)

Create a query for matching indexed float ranges that contain the defined range.

Parameters:

field - field name. must not be null.

min - array of min values. (accepts Float.NEGATIVE_INFINITY)

max - array of max values. (accepts Float.POSITIVE_INFINITY)

Returns:

query for matching ranges that contain the defined range

Throws:

IllegalArgumentException - if field is null, min or max is invalid

newWithinQuery

public static Query newWithinQuery(String field,
 float[] min,
 float[] max)

Create a query for matching indexed ranges that are within the defined range.

Parameters:

field - field name. must not be null.

min - array of min values. (accepts Float.NEGATIVE_INFINITY)

max - array of max values. (accepts Float.POSITIVE_INFINITY)

Returns:

query for matching ranges within the defined range

Throws:

IllegalArgumentException - if field is null, min or max is invalid

newCrossesQuery

public static Query newCrossesQuery(String field,
 float[] min,
 float[] max)

Create a query for matching indexed ranges that cross the defined range. A CROSSES is defined as any set of ranges that are not disjoint and not wholly contained by the query. Effectively, its the complement of union(WITHIN, DISJOINT).

Parameters:

field - field name. must not be null.

min - array of min values. (accepts Float.NEGATIVE_INFINITY)

max - array of max values. (accepts Float.POSITIVE_INFINITY)

Returns:

query for matching ranges within the defined range

Throws:

IllegalArgumentException - if field is null, min or max is invalid

newRelationQuery

private static Query newRelationQuery(String field,
 float[] min,
 float[] max,
 RangeFieldQuery.QueryType relation)

helper method for creating the desired relational query

toString

public String toString()

Description copied from class: Field

Prints a Field for human consumption.

Overrides:

toString in class Field

toString

private static String toString(byte[] ranges,
 int dimension)

Returns the String representation for the range at the given dimension

Parameters:

ranges - the encoded ranges, never null

dimension - the dimension of interest

Returns:

The string representation for the range at the provided dimension