org.apache.mahout.math.hadoop.similarity.cooccurrence.measures.VectorSimilarityMeasure Maven / Gradle / Ivy

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
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package org.apache.mahout.math.hadoop.similarity.cooccurrence.measures;

import org.apache.mahout.math.Vector;

public interface VectorSimilarityMeasure {

  double NO_NORM = 0.0;

  Vector normalize(Vector vector);
  double norm(Vector vector);
  double aggregate(double nonZeroValueA, double nonZeroValueB);
  double similarity(double summedAggregations, double normA, double normB, int numberOfColumns);
  boolean consider(int numNonZeroEntriesA, int numNonZeroEntriesB, double maxValueA, double maxValueB,
      double threshold);
}