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.regression.sgd;
018
019import com.oracle.labs.mlrg.olcut.config.Configurable;
020import com.oracle.labs.mlrg.olcut.provenance.ConfiguredObjectProvenance;
021import com.oracle.labs.mlrg.olcut.provenance.Provenancable;
022import com.oracle.labs.mlrg.olcut.util.Pair;
023import org.tribuo.math.la.DenseVector;
024import org.tribuo.math.la.SGDVector;
025
026/**
027 * An interface for regression objectives.
028 */
029public interface RegressionObjective extends Configurable, Provenancable<ConfiguredObjectProvenance> {
030
031    /**
032     * Scores a prediction, returning the loss.
033     * @param truth The true regression value.
034     * @param prediction The predicted regression value.
035     * @return A pair with the loss and gradient.
036     */
037    public Pair<Double, SGDVector> loss(DenseVector truth, SGDVector prediction);
038
039}