org.apache.lucene.search

Class DocValuesStats.NumericDocValuesStats<T extends Number>

java.lang.Object

org.apache.lucene.search.DocValuesStats<T>

org.apache.lucene.search.DocValuesStats.NumericDocValuesStats<T>

Direct Known Subclasses:

DocValuesStats.DoubleDocValuesStats, DocValuesStats.LongDocValuesStats

Enclosing class:

DocValuesStats<T>

public abstract static class DocValuesStats.NumericDocValuesStats<T extends Number>
extends DocValuesStats<T>

Holds statistics for a numeric DocValues field.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.search.DocValuesStats

DocValuesStats.DoubleDocValuesStats, DocValuesStats.LongDocValuesStats, DocValuesStats.NumericDocValuesStats<T extends Number>, DocValuesStats.SortedDocValuesStats, DocValuesStats.SortedDoubleDocValuesStats, DocValuesStats.SortedLongDocValuesStats, DocValuesStats.SortedNumericDocValuesStats<T extends Number>, DocValuesStats.SortedSetDocValuesStats

Field Summary

Fields

Modifier and Type	Field and Description
protected double	mean
protected NumericDocValues	ndv
protected double	variance

Fields inherited from class org.apache.lucene.search.DocValuesStats

field, max, min

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	NumericDocValuesStats(String field, T initialMin, T initialMax)

Method Summary

Modifier and Type	Method and Description
protected boolean	hasValue(int doc) Returns whether the given document has a value for the requested DocValues field.
protected boolean	init(LeafReaderContext context) Initializes this object with the given reader context.
double	mean() The mean of all values of the field.
double	stdev() Returns the stdev of all values of the field.
abstract T	sum() Returns the sum of values of the field.
double	variance() Returns the variance of all values of the field.

Methods inherited from class org.apache.lucene.search.DocValuesStats

count, doAccumulate, field, max, min, missing

Methods inherited from class java.lang.Object

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

Field Detail

mean

protected double mean

variance

protected double variance

ndv

protected NumericDocValues ndv

Constructor Detail

NumericDocValuesStats

protected NumericDocValuesStats(String field,
                                T initialMin,
                                T initialMax)

Method Detail

init

protected final boolean init(LeafReaderContext context)
                      throws IOException

Description copied from class: DocValuesStats

Initializes this object with the given reader context. Returns whether stats can be computed for this segment (i.e. it does have the requested DocValues field).

Specified by:

init in class DocValuesStats<T extends Number>

Throws:

IOException

hasValue

protected final boolean hasValue(int doc)
                          throws IOException

Description copied from class: DocValuesStats

Returns whether the given document has a value for the requested DocValues field.

Specified by:

hasValue in class DocValuesStats<T extends Number>

Throws:

IOException

mean

public final double mean()

The mean of all values of the field.

variance

public final double variance()

Returns the variance of all values of the field.

stdev

public final double stdev()

Returns the stdev of all values of the field.

sum

public abstract T sum()

Returns the sum of values of the field. Note that if the values are large, the sum might overflow.