hera_sim

|Build Status| |Coverage Status| |RTD|

Basic simulation package for HERA-like redundant interferometric arrays.

Features

• Systematic Models: Many models of instrumental systematics in various forms, eg. thermal noise, RFI, bandpass gains, cross-talk, cable reflections and foregrounds.
• HERA-tuned: All models have defaults tuned to HERA, with various default "sets" available (eg.H1C, H2C)
• Interoperability: Interoperability with pyuvdata datasets and pyuvsim configurations.
• Ease-of-use: High-level interface for adding multiple systematics to existing visibilities in a self-consistent way.
• Visibility Simulation: A high-level interface for visbility simulation that is compatible with the configuration definition from pyuvsim but is able to call multiple simulator implementations.
• Convenience: Methods for adjusting simulated data to match the times/baselines of a reference dataset.

Documentation

At ReadTheDocs <https://hera-sim.readthedocs.io/en/latest/>_. In particular, for a tutorial and overview of available features, check out the tour <https://hera-sim.readthedocs.io/en/latest/tutorials/hera_sim_tour.html>_.

Installation

Conda users

If you are using conda, the following command will install all
dependencies which it can handle natively:

``$ conda install -c conda-forge numpy scipy pyuvdata attrs h5py healpy pyyaml``

If you are creating a new development environment, consider using the
included environment file:

``$ conda env create -f ci/tests.yaml``

This will create a fresh environment with all required dependencies, as
well as those required for testing. Then follow the pip-only
instructions below to install ``hera_sim`` itself.

Pip-only install

Simply use pip install -e . or run pip install git+git://github.com/HERA-Team/hera_sim.

Developer install

For a development install (tests and documentation), run
``pip install -e .[dev]``.

Other optional extras can be installed as well. To use
baseline-dependent averaging functionality, install the extra ``[bda]``.
For the ability to simulate redundant gains, install ``[cal]``. To
enable GPU functionality on some of the methods (especially visibility
simulators), install ``[gpu]``.

As the repository is becoming quite large, you may also wish to perform
a shallow clone to retrieve only the recent commits and history. This makes
the clone faster and avoid bottleneck in CI pipelines.

Provide an argument ``--depth 1`` to the ``git clone`` command to copy only
the latest revision of the repository.

``git clone -–depth [depth] git@github.com:HERA-Team/hera_sim.git``

Versioning
----------

We use semantic versioning (``major``.\ ``minor``.\ ``patch``) for the
``hera_sim`` package (see `SemVer documentation <https://semver.org>`_).
To briefly summarize, new
``major`` versions include API-breaking changes, new ``minor`` versions
add new features in a backwards-compatible way, and new ``patch``
versions implement backwards-compatible bug fixes.

.. |Build Status| image:: https://github.com/HERA-Team/hera_sim/workflows/Tests/badge.svg
   :target: https://github.com/HERA-Team/hera_sim
.. |Coverage Status| image:: https://coveralls.io/repos/github/HERA-Team/hera_sim/badge.svg?branch=master
   :target: https://coveralls.io/github/HERA-Team/hera_sim?branch=master
.. |RTD| image:: https://readthedocs.org/projects/hera-sim/badge/?version=latest
   :target: https://hera-sim.readthedocs.io/en/latest/?badge=latest
   :alt: Documentation Status