001 /*
002 * Java Genetic Algorithm Library (jenetics-7.1.0).
003 * Copyright (c) 2007-2022 Franz Wilhelmstötter
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 *
017 * Author:
018 * Franz Wilhelmstötter (franz.wilhelmstoetter@gmail.com)
019 */
020 package io.jenetics.prog.regression;
021
022 import java.util.List;
023 import java.util.function.Function;
024
025 import io.jenetics.ext.util.Tree;
026
027 import io.jenetics.prog.op.Op;
028
029 /**
030 * This interface represents a set of sample points, which can be evaluated with
031 * a given evolved <em>program</em>.
032 *
033 * @author <a href="mailto:franz.wilhelmstoetter@gmail.com">Franz Wilhelmstötter</a>
034 * @version 7.1
035 * @since 6.0
036 */
037 @FunctionalInterface
038 public interface Sampling<T> {
039
040 /**
041 * This class represents the result of a sample calculation, which contains
042 * the array of calculated values and a corresponding array with expected
043 * sample values. This two arrays can then be used for calculating the
044 * error between modeled regression function and actual sample values.
045 *
046 * @param <T> the sample result type
047 */
048 record Result<T>(T[] calculated, T[] expected) {
049 /**
050 * @param calculated the calculated result values
051 * @param expected the expected sample result values
052 * @throws NullPointerException if one of the arguments is {@code null}
053 */
054 public Result {
055 calculated = calculated.clone();
056 expected = expected.clone();
057 }
058 }
059
060 /**
061 * Evaluates the given {@code program} tree with its sample points. The
062 * returned result object may be {@code null} if no sample point has been
063 * added to the <em>sampling</em> when calling the {@code eval} method.
064 *
065 * @param program the program to evaluate
066 * @return the evaluated sample result. May be {@code null} if the sampling
067 * is empty and contains no sample points.
068 */
069 //@Deprecated(since = "7.1", forRemoval = true)
070 Result<T> eval(final Tree<? extends Op<T>, ?> program);
071
072 /**
073 * Evaluates the given {@code function} tree with its sample points. The
074 * returned result object may be {@code null} if no sample point has been
075 * added to the <em>sampling</em> when calling the {@code eval} method.
076 *
077 * @param function the function to evaluate
078 * @return the evaluated sample result. May be {@code null} if the sampling
079 * is empty and contains no sample points.
080 */
081 default Result<T> eval(final Function<? super T[], ? extends T> function) {
082 throw new UnsupportedOperationException();
083 }
084
085 /**
086 * Create a new sampling object from the given sample points.
087 *
088 * @since 7.1
089 *
090 * @param samples the sample points
091 * @param <T> the sample type
092 * @return a new sampling object
093 */
094 static <T> Sampling<T> of(final List<? extends Sample<T>> samples) {
095 return new SampleList<>(samples);
096 }
097
098 /**
099 * Create a new sampling object from the given sample points.
100 *
101 * @since 7.1
102 *
103 * @param samples the sample points
104 * @param <T> the sample type
105 * @return a new sampling object
106 */
107 @SafeVarargs
108 static <T> Sampling<T> of(final Sample<T>... samples) {
109 return Sampling.of(List.of(samples));
110 }
111
112 }
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