skiehl / polarizationtools

Tools to deal with astrophysical polarization data in python3

polarizationtools

Python3 tools to deal with astrophysical polarization data.

Modules

• evpatools.py Tools to analyze EVPA time series data.
• misc.py Miscellaneous tools.
• randomwalk.py Simulate random walks in the Stokes Q-U plane.
• stokesconversion.py Convert Stokes parameters into linear polarization parameters and vice versa.

Module details

• evpatools.py
  • EVPAanalyzer class:
    • Shift EVPA data points to account for the 180 degrees ambiguity, following [1].
    • Identify rotations according to the definitions of [4] or [1].
• misc.py
  • debias_pol function: Debias the fractional linear polarization, following [2].
• randomwalk.py
  • RWsim class: Simulate random walks in the Stokes Q-U plane, following [1].
• stokesconversion.py
  • StokesConversion class: Convert Stokes parameters into linear polarization parameters with proper treatment of the uncertainties as explained in [3].
  • StokesConversionSimple class: Convert Stokes parameters into linear polarization parameters and vice versa with simple Gaussian error propagation.

Citation

Bibtex:

@software{2024ascl.soft02006K,
       author = {{Kiehlmann}, Sebastian},
        title = "{polarizationtools: Polarization analysis and simulation tools in python}",
 howpublished = {Astrophysics Source Code Library, record ascl:2402.006},
         year = 2024,
        month = feb,
          eid = {ascl:2402.006},
       adsurl = {https://ui.adsabs.harvard.edu/abs/2024ascl.soft02006K},
      adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}

This software package is indexed on ASCL and ADS.

License

polarizationtools is licensed under the BSD 3-Clause License - see the LICENSE file.

References

1. Kiehlmann et al, 2016
2. Pavlidou et al, 2014
3. Blinov et al, 2021
4. Blinov et al, 2015

polarizationtools's Issues

Add random walk models

I want to add my random walk simulation code to this package.

Absolute threshold in smooth rotation identification broken?

I am not absolutely certain that the absolute threshold is implemented correctly in evpatools.EVPAanalyzer._identify_rot_smooth(). This needs some checks.
It is implemented and can be used. The user is warned that the results may not be correct.

Add error propagation in smooth rotation identification for threshold factor

This regards the _identify_rot_smooth() method in evpatools.EVPAanalyzer. Currently error propagation is only implemented for the absolute threshold. A placeholder for this feature exists, but calling it results in NotImplementedError.

Add MCoR adjustment

Implement _adjust_mcor() method in evpatools.EVPAanalyzer. A placeholder method already exists.