# Introduction

[This package](https://cma-es.github.io/moarchiving/moarchiving-apidocs/index.html) implements a multi-objective 
 non-dominated archive for 2, 3 or 4 objectives, providing easy and fast access to multiple hypervolume indicators:

- the hypervolume of the entire archive,
- the contributing hypervolume of each element,
- the [uncrowded hypervolume improvement](https://doi.org/10.1145/3321707.3321852) (see also [here](https://arxiv.org/abs/1904.08823)) of any given point in the objective space, and
- the uncrowded hypervolume of the (unpruned) archive, here called [hypervolume plus](https://cma-es.github.io/moarchiving/moarchiving-apidocs/moarchiving.moarchiving.BiobjectiveNondominatedSortedList.html#hypervolume_plus).

Additionally, the package provides a constrained version of the archive,
which allows to store points with constraints.

The source code is available [on GitHub](https://github.com/CMA-ES/moarchiving).

## Installation

On a system shell, either like
```
pip install moarchiving
```

or from GitHub, for example
```
pip install git+https://github.com/CMA-ES/moarchiving.git@development
```
installing from the `development` branch.