Welcome to HEALPix Multi-Order Coordinate Library (HPMOC)’s documentation!
HPMOC is an ultra high-performance, cross-platform toolset for working with multi-order coordinate (MOC) HEALPix images (i.e. images with multiple pixel resolutions). MOC images are used by LIGO and others to represent portions of the sky with variable resolution. By only including pixels in regions of interest, and only then at a resolution appropriate to how they were observed/calculated, it is possible to reduce storage and computation costs by several orders of magnitude.
HPMOC is the only library providing tools for loading partial/whole MOC skymaps (as well as standard HEALPix skymaps), taking spatial intersections, modifying resolution, plotting the skymaps, converting them to and from Astropy WCS projections, performing pointwise math, and generating PSF skymaps from point sources, all using algorithms that minimize memory, computation, and storage costs. It is based off of work on LLAMA, the world’s first Gravitational Wave/High-Energy Neutrino low-latency search pipeline, which has been improved and refactored into this separate module.
If you are interested in using HPMOC for your research, or if you have questions about it, reach out to the author.
Installation
hpmoc has only a few dependencies, but they are large numerical/scientific
libraries. You should therefore probably create a virtual environment of some
sort before installing. The easiest and best way to do this at the moment is to
use conda, which should come with an Anaconda distribution of Python:
conda create -n hpmoc
conda activate hpmoc
With pip
If you just want to use hpmoc and don’t need to modify the source code, you
can install the last released version (link in source repo README) using pip:
pip install hpmoc-latest-py3-none-any.whl
This should install all required dependencies for you.
Developer Installation
If you want to install from source (to try the latest, unreleased version, or to make your own modifications, run tests, etc.), first clone the repository:
git clone git@bitbucket.org:stefancountryman/hpmoc.git
cd hpmoc
Make sure the build tool, flit, is installed:
pip install flit
Then install an editable version of hpmoc with flit:
flit install --symlink
As with the pip installation method, this should install all requirements for
you. You should now be able to import hpmoc. Note that you’ll need to quit
your python session (or restart the kernel in Jupyter) and reimport hpmoc
before your changes to the source code take effect (which is true for any
editable Python installation, FYI).
You can go ahead and run the tests with pytest (which should have been
installed automatically by flit):
py.test --doctest-modules --cov=hpmoc
Examples
API Documentation