Add method that returns values/pulsars given a logical condition

PSRQpy

This module aims to provide a python interface for querying the ATNF pulsar catalogue. It is an unofficial package and is not endorsed by or affiliated with the ATNF.

Full documentation of the module can be found here.

Any comments or suggestions are welcome.

Installation

To install the code from source, clone the git repository and run either:

python setup.py install --user

to install as a user, or

sudo python setup.py install

to install as root.

The module can also be installed using pip with:

pip install psrqpy

or in a Conda environment using:

conda install -c conda-forge psrqpy

Requirements

The requirements for installing the code are:

Examples

A simple query of the catalogue to, e.g., just return all pulsar frequencies, would be:

import psrqpy

q = psrqpy.QueryATNF(params='F0')

# get frequencies as an astropy table
t = q.table

print(t['F0'])

You can query multiple parameters, e.g.:

import psrqpy

q = psrqpy.QueryATNF(params=['F0', 'F1', 'RAJ', 'DecJ'])

# get values as an astropy table
t = q.table

print(t['F0'])

You can query specific pulsars, e.g.:

import psrqpy

q = psrqpy.QueryATNF(params=['F0', 'F1', 'RAJ', 'DecJ'], psrs=['J0534+2200', 'J0537-6910'])

# get values as an astropy table
t = q.table

# print the table
print(t)
  JNAME          F0       F0_ERR       F1      F1_ERR     RAJ      RAJ_ERR     DECJ     DECJ_ERR
                 Hz         Hz       1 / s2    1 / s2                                           
---------- ------------- ------- ------------- ------ ------------ ------- ------------ --------
J0534+2200     29.946923   1e-06  -3.77535e-10  2e-15 05:34:31.973   0.005 +22:00:52.06     0.06
J0537-6910 62.0261895958 1.3e-09 -1.992272e-10  4e-17 05:37:47.416    0.11 -69:10:19.88      0.6

You can set conditions for the searches, e.g.:

import psrqpy
q = psrqpy.QueryATNF(params=['Jname', 'f0'], condition='f0 > 100 && f0 < 200', assoc='GC')

where assoc=GC looks for all pulsars in globular clusters.

When a query is generated the entire catalogue is downloaded and stored in the QueryATNF object as a pandas DataFrame. The query can therefore be re-used to access data on different parameters, different pulsars, or using different conditions, without the need to re-download the catalogue. We may originally want to query pulsar frequencies using only frequencies greater than 10 Hz, with

import psrqpy
q = psrqpy.QueryATNF(params=['F0'], condition='F0 > 10')
freqs = q.table['F0']

Using the same QueryATNF object we could change to get frequency derivatives for pulsars with frequencies less than 10 Hz, with

q.condition = 'F0 < 10'
q.query_params = 'F1'

fdot = q.table['F1']

In these cases the whole catalogue (with no conditions applied and all available parameters) stored as a pandas DataFrame is accessible with

catalogue = q.catalogue

You can also generate a lovely period vs. period derivative plot based on the latest catalogue information, using just three lines of code, e.g.:

from psrqpy import QueryATNF
query = QueryATNF(params=['P0', 'P1', 'ASSOC', 'BINARY', 'TYPE', 'P1_I'])
query.ppdot(showSNRs=True, showtypes='all')

gives

Development and Support

Code development is done via the package's GitHib repository. Any contributions can be made via a fork and pull request model from that repository, and must adhere to the MIT license. Any problems with the code or support requests can be submitted via the repository's Issue tracker.

Test suite

There are tests supplied that cover many of the functions within PSRQpy. These can be run from the base directory of the repository (after installing the pytest and pytest-socket modules, e.g., with pip) by just calling:

pytest

These tests are not included in the pip installed version of the code.

Copyright and referencing for the catalogue

Regarding the use of the catalogue and software behind it, the following statements apply:

PSRCAT is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. PSRCAT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

PSRCAT makes use of "evaluateExpression: A Simple Expression Evaluator". Copyright © 1996 - 1999 Parsifal Software, All Rights Reserved.

The programs and databases remain the property of the Australia Telescope National Facility, CSIRO, and are covered by the CSIRO Legal Notice and Disclaimer.

If you make use of information from the ATNF Pulsar Catalogue in a publication, we would appreciate acknowledgement by reference to the publication "The ATNF Pulsar Catalogue", R. N. Manchester, G. B. Hobbs, A. Teoh & M. Hobbs, Astronomical Journal, 129, 1993-2006 (2005) and by quoting the web address http://www.atnf.csiro.au/research/pulsar/psrcat for updated versions.

If making use of this code to access the catalogue, or produce plots, I would be grateful if (as well as citing the ATNF pulsar catalogue paper and URL given above) you consider citing the JOSS paper for this software:

@article{psrqpy,
  author = {{Pitkin}, M.},
   title = "{psrqpy: a python interface for querying the ATNF pulsar catalogue}",
  volume = 3,
  number = 22,
   pages = 538,
   month = feb,
    year = 2018,
 journal = "{Journal of Open Source Software}",
     doi = {10.21105/joss.00538},
     url = {https://doi.org/10.21105/joss.00538}
}