jMetal 6 project Web site

jMetal is a Java-based framework for multi-objective optimization with metaheuristics. The current stable version is 5.8 (https://github.com/jMetal/jMetal/tree/jmetal-5.8), which is based on the description of jMetal 5 included in the paper "Redesigning the jMetal Multi-Objective Optimization Framework" (http://dx.doi.org/10.1145/2739482.2768462), presented at GECCO 2015.

After five years working with jMetal 5, a new major release, jMetal 6, is under development and, after some months working of a development branch, it has been moved to the master branch as version 6.0-SNAPSHOT.

A summary of the features of jMetal 6.0 are listed next:

• jMetal 6 requires Java 11.
• The default format for files containing fronts (including the reference Pareto fronts) is CSV.
• Use of Sphinx for the documentation. In jMetal 5 the documentation is based on Markdown files; it is not complete and some parts are outdated (this documentation is still available: https://github.com/jMetal/jMetalDocumentation). The documentation of jMetal 6 is being elaborated here: https://jmetal.readthedocs.io/en/latest/.
• Support for automatic configuration of metaheuristics. We include a sub-project called jmetal-auto, which currently contains a version of NSGA-II that can be fully auto tuned using irace, as is described in the paper "Automatic Configuration of NSGA-II with jMetal and irace", presented at GECCO 2019 (DOI: https://doi.org/10.1145/3319619.3326832).
• Improved experimentation. The output of an experiment (i.e., the execution of a number of algorithms on a set of problems) is an CSV file which can be further analyzed to produce Latex tables and graphics with statistical information. We plan to use Tablesaw (https://github.com/jtablesaw/tablesaw) and Smile (http://haifengl.github.io/smile/) for analysis tasks and for visualization. All the experimentation code is located in a new sub-package called jmetal-lab.
• All the core packages in jmetal-core (solution, problem, algorithm, operator, quality indicator), are being revised, tested, and refactored. The same applies to the jmetal-core/util package.
• The implementation of the algorithms in jmetal-algorithm will be revised.

jMetal 6 is implemented in Java 8 (although I plan to change to Java 11) and it is a Maven project structured in six sub-projects:

Sub-project	Contents
jmetal-core	Core classes
jmetal-solution	Solution encodings
jmetal-algorithm	Algorithm implementations
jmetal-problem	Benchmark problems
jmetal-example	Examples
jmetal-lab	Experimentation
jmetal-auto	Auto configuration

All the code included in jMetal 5.8 is included in jMetal 6.0-SNAPSHOT, so the project is fully functional and we are currently using it in our research work.

Comments and suggestions are very welcome.

Changelog

• [3/19/2020] New quality indicator: NormalizedHypervolume.
• [3/19/2020] The jMetal 6 project is changed to use Java 11.
• [2/11/2020] All the files containing Pareto front approximations and weight vectors have been moved to the resources folder, located in root project directory.
• [2/06/2020] New implementation of the SMS-EMOA algorithm based on a component-based scheme.
• [1/23/2020] A solution encoding for defining solution having mixed internal representations has been developed using class CompositeSolution. This class acts as solution container, so their variables are solutions of any kind. Variation operators for this class have been developed (classes CompositeCrossover and CompositeMutation). An example of configuring and running NSGA-II to solve a problem using this encoding is available in class NSGAIIWithMixedSolutionEncodingExample. Any feedback about this new feature is welcome.
• [1/13/2020] New implementation of the MOEA/D algorithm based on a component-based scheme. A description of the implementation and examples of using it can be found in the documentation.
• [12/10/2019] Merge non dominated sorting algorithm (contributed by Javier Moreno), described in "Merge Non-Dominated Sorting Algorithm for Many-Objective Optimization" . The code is included in (class org.uma.jmetal.component.ranking.MergeNonDominatedSortRanking). An example of using this class in NSGA-II is contained in NSGAIIWithMNDSRankingExample.
• [12/02/2019] New implementation of NSGA-II (class org.uma.jmetal.algorithm.multiobjective.nsgaii). This class is documented here.
• [12/02/2019] Experimental non dominated sorting algorithm (contributed by Maxim Buzdalov). The code is included in (class org.uma.jmetal.component.ranking.ExperimentalFastNonDominanceRanking). An example of using this class in NSGA-II is contained in NSGAIIWithExperimentalNDSAlgorithmExample.