org.apache.lucene.search.similarities

## Class DistributionSPL

- java.lang.Object
- - org.apache.lucene.search.similarities.Distribution
  - - org.apache.lucene.search.similarities.DistributionSPL

-     public class DistributionSPL
      extends Distribution

  The smoothed power-law (SPL) distribution for the information-based framework that is described in the original paper.

  Unlike for DFR, the natural logarithm is used, as it is faster to compute and the original paper does not express any preference to a specific base.

  WARNING: this model currently returns infinite scores for very small tf values and negative scores for very large tf values
  WARNING: This API is experimental and might change in incompatible ways in the next release.

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `DistributionSPL()` Sole constructor: parameter-free

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `double` | `score(BasicStats stats, double tfn, double lambda)` Computes the score.
    `String` | `toString()` Subclasses must override this method to return the name of the distribution.

    - ### Methods inherited from class org.apache.lucene.search.similarities.Distribution

      `explain`

    - ### Methods inherited from class java.lang.Object

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

- - ### Constructor Detail

    - #### DistributionSPL

          public DistributionSPL()

      Sole constructor: parameter-free

  - ### Method Detail

    - #### score

          public final double score(BasicStats stats,
                                    double tfn,
                                    double lambda)

      Description copied from class: `Distribution`
      Computes the score.
      Specified by:
        `score` in class `Distribution`

    - #### toString

          public String toString()

      Description copied from class: `Distribution`
      Subclasses must override this method to return the name of the distribution.
      Specified by:
        `toString` in class `Distribution`

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