Package org.apache.lucene.misc.search

Class DocValuesStats.NumericDocValuesStats<T extends Number>

java.lang.Object
org.apache.lucene.misc.search.DocValuesStats<T>
org.apache.lucene.misc.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.

  • Field Details

    • mean

      protected double mean

    • variance

      protected double variance

    • ndv

      protected NumericDocValues ndv

  • Constructor Details

    • NumericDocValuesStats

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

  • Method Details

    • 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.

    • merge

      protected void merge(DocValuesStats<T> other)
      Description copied from class: DocValuesStats
      Merges the statistics from other into this instance. After the call, this instance reflects the combined statistics of both segments as if they had been collected together. Subclasses that track additional statistics (e.g. mean, variance, sum) must override this method, call super.merge(other), and combine their own fields accordingly.
      Overrides:
      merge in class DocValuesStats<T extends Number>
      Parameters:
      other - the stats instance to merge into this one; must be of the same concrete type