pycorrelator

A Python package for cross correlation and self correlation in spherical coordinates.

Table of Contents

• Introduction
• Features
• Installation
• Example Usage
• API Reference
• Contributing
• Citation

Introduction

pycorrelator is a Python package designed to perform cross correlation and self correlation analyses in spherical coordinates. This is particularly useful in fields such as astrophysics, geophysics, and any domain where objects are naturally distributed on a spherical surface. Currently, this package only support astrophysics coordinates (Ra, Dec) in degrees. More units and naming convention will be supported in the future.

Features

• Efficient computation ( $O(N\log N)$ ) of cross correlation in spherical coordinates.
• Friends-of-Friends (FoF) analysis in spherical coordinates.
• Duplicate removal in spherical coordinates.
• Easy integration with existing data processing packages, such as pandas.

Installation

You can install pycorrelator by cloning the codes:

git clone https://github.com/technic960183/pycorrelator.git

pip install will be supported in the future.

Remember to set the environment variable PYTHONPATH (sys.path) to the directory where pycorrelator is located. See the installation guide for more details.

Example Usage

Before you start, please check out our documentation for a quick start.

• To perform cross-matching between two catalogs, check this cross-matching example.
• To cluster the objects in a catalog with the Friends-of-Friends (FoF) algorithm, check this clustering example.
• To remove duplicates from a catalog, check this duplicate removal example.

API Reference

The full documentation and API reference can be found here.

Contributing

If you find any bugs or potential issues, please report it directly to me (via Slack or E-mail), or start an issue.

If you have any suggestions or feature requests, feel free to start an issue.

Citation

If you find pycorrelator useful in your research, please consider citing it. Currently, we do not plan to publish a method paper for this package in the year of 2024. However, you can still cite this repository directly.

To cite pycorrelator in your publication, please use the following BibTeX entry:

@misc{pycorrelator,
  author = {Yuan-Ming Hsu},
  title = {pycorrelator: A Python package for cross correlation and self correlation in spherical coordinates.},
  year = {2024},
  howpublished = {\url{https://github.com/technic960183/pycorrelator}},
  note = {Accessed: YYYY-MM}
}

Addtionally, you may add a reference to https://github.com/technic960183/pycorrelator in the footnote if suitable.

If you publish a paper that uses pycorrelator, please let me know. I would be happy to know how this package has been used in research.