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package org.apache.lucene.search.similarities;


Log-logistic distribution.

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.

@lucene.experimental
/** * Log-logistic distribution. * <p>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.</p> * @lucene.experimental */
public class DistributionLL extends Distribution {
Sole constructor: parameter-free
/** Sole constructor: parameter-free */
public DistributionLL() {} @Override public final double score(BasicStats stats, double tfn, double lambda) { return -Math.log(lambda / (tfn + lambda)); } @Override public String toString() { return "LL"; } }