jenetics

/*
 * Copyright (c) 2023 Franz Wilhelmstötter
 *
 * Licensed 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

jenetics

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.EOFException;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.UncheckedIOException;

jenetics

import io.jenetics.DoubleGene;
import io.jenetics.EnumGene;
import io.jenetics.Genotype;
import io.jenetics.engine.Codec;
import io.jenetics.engine.Codecs;
import io.jenetics.engine.Engine;
import io.jenetics.engine.EvolutionResult;
import io.jenetics.util.DoubleRange;
import io.jenetics.util.ProxySorter;

jenetics

/*
 * This codec creates a split range, where only values between [0, 2) and
 * [8, 10) are valid. The valid range is marked with '-' and the invalid
 * range with 'x'.
 *
 *   +--+--+--+--+--+--+--+--+--+--+
 *   |  |  |  |  |  |  |  |  |  |  |
 *   0  1  2  3  4  5  6  7  8  9  10
 *   |-----|xxxxxxxxxxxxxxxxx|-----|
 *      ^  |llllllll|rrrrrrrr|  ^

jenetics

import static java.util.Collections.emptyList;
import static io.jenetics.engine.EvolutionResult.toBestPhenotype;

import java.util.List;
import java.util.function.Function;
import java.util.stream.DoubleStream;
import java.util.stream.Stream;

import io.jenetics.DoubleChromosome;
import io.jenetics.DoubleGene;

jenetics

import static java.lang.String.format;

import java.util.Comparator;

/**
 * Sample implementation of a 3D double point.
 */
public final class Point3 implements Vec<Point3> {
    private final double _x;
    private final double _y;

jenetics

void sortStringArray() {
	final String[] strings = new String[]{"g", "f", "r", "u", "a"};
	final int[] proxy = ProxySorter.sort(
		strings, strings.length,
		(a, i, j) -> a[i].compareTo(a[j])
	);

	// Printing strings in ascending order.
	for (int index : proxy) {
		System.out.println(strings[index]);

jenetics

final class Polynomial {
    private final double[] a;

    Polynomial(final double... a) {
        this.a = a.clone();
    }

    // Uses Horner's Method to evaluate the polynomial.
    double apply(final double x) {
        double result = a[a.length - 1];

jenetics

final Error error = Error.of(
    LossFunction::mse,
    Complexity.ofMaxNodeCount(50)
);

jenetics

private static final Regression<Double> REGRESSION = Regression.of(
    Regression.codecOf(OPERATIONS, TERMINALS, 5),
    Error.of(LossFunction::mse),
    Sample.ofDouble(-1.0, -8.0000),
    // ...
    Sample.ofDouble(0.9, 1.3860),
    Sample.ofDouble(1.0, 2.0000)
);

public static void main(final String[] args) {