org.apache.commons.statistics.ranking.RankingAlgorithm 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
* limitations under the License.
*/
package org.apache.commons.statistics.ranking;
import java.util.function.UnaryOperator;
/**
* Interface representing a rank transformation.
*
* @since 1.1
*/
@FunctionalInterface
public interface RankingAlgorithm extends UnaryOperator {
/**
* Performs a rank transformation on the input data, returning an array of
* ranks.
*
*
Ranks should be 1-based: the smallest value returned in an array of ranks
* should be greater than or equal to one, rather than 0. Ranks should in
* general take integer values, though implementations may return averages or
* other floating point values to resolve ties in the input data.
*
* @param data Array of data to be ranked.
* @return an array of ranks corresponding to the elements of the input array
*/
@Override
double[] apply(double[] data);
}