@syntest/search
Version:
The common core of the SynTest Framework
49 lines • 2.15 kB
JavaScript
;
/*
* Copyright 2020-2021 Delft University of Technology and SynTest contributors
*
* This file is part of SynTest Framework - SynTest Core.
*
* 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
* 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.
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.tournamentSelection = void 0;
const prng_1 = require("@syntest/prng");
const diagnostics_1 = require("../../util/diagnostics");
/**
* This function selects the individual for reproduction using tournament selection
* @param population the population from which to select a parent
* @param tournamentSize size of the tournament (minimum 2)
* @returns AbstractTestCase selected individual
*
* @author Annibale Panichella
*/
function tournamentSelection(population, tournamentSize) {
if (tournamentSize < 2)
throw new Error((0, diagnostics_1.minimumValue)("tournament size", 2, tournamentSize));
let winner = prng_1.prng.pickOne(population);
for (let tournament = 0; tournament < tournamentSize - 1; tournament++) {
const solution = prng_1.prng.pickOne(population);
// The winner is the solution with the best (smaller) non-dominance rank.
// At the same level or ranking, the winner is the solution with the best (largest)
// crowding distance.
if (solution.getRank() < winner.getRank() ||
(solution.getRank() === winner.getRank() &&
solution.getCrowdingDistance() > winner.getCrowdingDistance())) {
winner = solution;
}
}
return winner;
}
exports.tournamentSelection = tournamentSelection;
//# sourceMappingURL=TournamentSelection.js.map