Polycomp

This package provides a set of Python bindings to the libpolycomp library (https://github.com/ziotom78/libpolycomp), as well as a stand-alone program which can be used to compress/decompress FITS files into polycomp files (still FITS files in disguise).

This code has been indexed in the Astrophysics Source Code Library as [ascl:1604.002].

The paper Polycomp: efficient and configurable compression of astronomical timelines has been accepted by the Journal "Astronomy & Computing" (http://dx.doi.org/10.1016/j.ascom.2016.04.004). The preprint is available on arXiv.

Requirements

1. Either Python 2.7 or 3.4 will work
2. Libpolycomp (https://github.com/ziotom78/libpolycomp) must already be installed
3. The following Python libraries are required:
   • click (http://click.pocoo.org/5/);
   • numpy (http://www.numpy.org/);
   • Either astropy (version 0.4 or greater, http://www.astropy.org/) or pyfits (http://www.stsci.edu/institute/software_hardware/pyfits). (The setup.py script installs Astropy.);
   • Cython (http://cython.org/).

Note: Recent versions of NumPy (1.10) seem to be incompatible with PyFits 3.3: saving files will lead to strange assertion errors. NumPy 1.8.2 and PyFits 3.3 are fine. Or better, install AstroPy.

Installation

Once you have installed all the requirements, run the following command to install the library:

pip install .

You might have to make Python aware of the directory where libpolycomp.so was installed, if this is a non-standard location (this might include /usr/local/lib, which is the default path used by Libpolycomp when running make install). Just set the LD_LIBRARY_PATH variable to the correct path:

export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH

Basic usage

To use the bindings in your code, simply import pypolycomp in your project:

import pypolycomp

This package provides also a standalone program, polycomp. Use the --help flag to get some help about how to use it:

$ polycomp --help

How to cite this library

If you use this library in your work, please cite the paper Polycomp: efficient and configurable compression of astronomical timelines (http://dx.doi.org/10.1016/j.ascom.2016.04.004):

@article{Tomasi201688,
        title = "Polycomp: Efficient and configurable compression of astronomical timelines",
        journal = "Astronomy and Computing",
        volume = "16",
        number = "",
        pages = "88-98",
        year = "2016",
        issn = "2213-1337",
        doi = "http://dx.doi.org/10.1016/j.ascom.2016.04.004",
        author = "M. Tomasi",
}

License

This code is released under the MIT license.