| /* |
| * 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.wayang.profiler.log; |
| |
| import java.util.Random; |
| |
| /** |
| * A variable that can be altered by an optimization algorithm. |
| */ |
| public class Variable { |
| |
| private final String id; |
| |
| private final int index; |
| |
| private double minValue = 0d, maxValue = Double.POSITIVE_INFINITY; |
| |
| public Variable(int index, String id) { |
| this.index = index; |
| this.id = id; |
| } |
| |
| public String getId() { |
| return this.id; |
| } |
| |
| public double getValue(Individual individual) { |
| return individual.getGenome()[this.index]; |
| } |
| |
| public double createRandomValue(Random random) { |
| if (!Double.isFinite(this.minValue)) { |
| if (!Double.isInfinite(this.maxValue)) |
| return random.nextGaussian() * 1e9; |
| else |
| return this.maxValue - Math.abs(random.nextGaussian()) * 1e9; |
| } else if (!Double.isFinite(this.maxValue)) { |
| return this.minValue + Math.abs(random.nextGaussian()) * 1e9; |
| } |
| return random.nextDouble() * (this.maxValue - this.minValue) + this.minValue; |
| } |
| |
| public double mutate(double currentValue, Random random) { |
| final double deltaSmoothing = 1E-9; |
| if (!Double.isFinite(this.minValue)) { |
| if (!Double.isInfinite(this.maxValue)) { |
| return currentValue + random.nextGaussian() * Math.abs(currentValue); |
| } else { |
| double delta = this.maxValue - currentValue; |
| return this.maxValue - Math.abs(random.nextGaussian()) * delta; |
| } |
| } else if (!Double.isFinite(this.maxValue)) { |
| double delta = currentValue - this.minValue + deltaSmoothing; |
| final double randomGene = currentValue + random.nextGaussian() * delta / 2; |
| return randomGene < this.minValue ? |
| 2 * this.minValue - randomGene : |
| randomGene; |
| } |
| return random.nextDouble() * (this.maxValue - this.minValue) + this.minValue; |
| } |
| |
| public void setRandomValue(Individual individual, Random random) { |
| double randomValue = this.createRandomValue(random); |
| individual.setGene(this.index, randomValue, Double.NaN); |
| } |
| |
| public int getIndex() { |
| return index; |
| } |
| |
| @Override |
| public String toString() { |
| return "Variable[id=" + id + ", index=" + index + ']'; |
| } |
| } |