001/*
002 * Copyright (c) 2015-2020, Oracle and/or its affiliates. All rights reserved.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.tribuo.transform;
018
019import java.io.Serializable;
020
021/**
022 * A fitted {@link Transformation} which can apply
023 * a transform to the input value. Usually contains
024 * feature specific information from the training data.
025 * <p>
026 * Transformers are serializable, and should only
027 * be constructed by their {@link TransformStatistics}.
028 */
029public interface Transformer extends Serializable {
030
031    /**
032     * Applies the transformation to the supplied
033     * input value.
034     * @param input The value to transform.
035     * @return The transformed value.
036     */
037    public double transform(double input);
038
039}