org.apache.commons.statistics.ranking.TiesStrategy Maven / Gradle / Ivy
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* (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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.statistics.ranking;
/**
* Strategies for handling tied values in rank transformations.
*
* @since 1.1
*/
public enum TiesStrategy {
/**
* Ties are assigned ranks in order of occurrence in the original array.
*
* For example, {@code [1, 3, 4, 3]} is ranked as {@code [1, 2, 4, 3]}.
*/
SEQUENTIAL,
/**
* Tied values are assigned the minimum applicable rank, or the rank of the
* first occurrence.
*
*
For example, {@code [1, 3, 4, 3]} is ranked as {@code [1, 2, 4, 2]}.
*/
MINIMUM,
/**
* Tied values are assigned the maximum applicable rank, or the rank of the last
* occurrence.
For example, {@code [1, 3, 4, 3]} is ranked as {@code [1, 3, 4, 3]}.
*/
MAXIMUM,
/**
* Tied values are assigned the average of the applicable ranks.
*
*
For example, {@code [1, 3, 4, 3]} is ranked as {@code [1, 2.5, 4, 2.5]}.
*/
AVERAGE,
/**
* Tied values are assigned a unique random integral rank from among the
* applicable values.
*
*
For example, {@code [1, 3, 4, 3]} is ranked as either {@code [1, 2, 4, 3]} or
* {@code [1, 3, 4, 2]} where the choice is random.
*
*
The assigned rank will always be an integer, (inclusively) between the
* values returned by the {@link #MINIMUM} and {@link #MAXIMUM} strategies.
*
*
Use of a unique rank ensures that ties are resolved so that the
* rank order is stable.
*/
RANDOM
}