/**
* 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.mahout.cf.taste.transforms;
import org.apache.mahout.cf.taste.common.Refreshable;
/**
* <p>
* Implementations encapsulate some transformation on similarity values between two things, where things might
* be IDs of users or items or something else.
* </p>
*/
public interface SimilarityTransform extends Refreshable {
/**
* @param value
* original similarity between thing1 and thing2 (should be in [-1,1])
* @return transformed similarity (should be in [-1,1])
*/
double transformSimilarity(long id1, long id2, double value);
}