astrosica / astrolic

Line Integral Convolution (LIC) for astrophysics polarization.

astroLIC

An implementation of LicPy using astronomical polarimetry. An example is given in a Jupyter notebook which reproduces Figure 2 in Campbell et al. (2020).

Dependencies

Required packages for LicPy:

• pybind11
• tensorflow
• matplotlib
• pytest
• sympy

Additional required packages for astroLIC:

• numpy
• aplpy
• astropy

There is currently a bug with using the latest version of tensorflow that results in the error AttributeError: module 'tensorflow' has no attribute 'placeholder' when running LicPy. To work around this, you'll want to open the lic.py file; for me this is located in /opt/anaconda3/lib/python3.7/site-packages/licpy-0.2-py3.7-macosx-10.9-x86_64.egg/licpy/. When the error is raised, you should be able to read off the directory that is causing the error. Then, simply change import tensorflow as tf to the following:

import tensorflow.compat.v1 as tf tf.disable_v2_behavior().

Installation

TBA.

Usage

astroLIC(I_dir,Q_dir,U_dir,length=0.25,toIAU=False,wcs=True)

Notes

This is a particular implementation of LIC meant for astronomical polarimetry which uses a specific coordinate system (IAU convention) not used in many other data sets. Therefore, astro-LIC is only meant to be used for astronomical polarization data and will not provide the correct orientation if used with other data sets.