HOLICs Code for Measuring Flexions in Python

This is a python code for demonstrating how to measure gravitational lensing flexion. This python code is translated from Goldberg's HOLICs code in IDL.

It includes two parts:

Illustrating what flexion is (see Fig. 1).

Use the command below to rebuild Fig. 1.

$ python2.7 show_flexion.py

Figure.1: This figure shows an input circle source and its lensed image with flexions. In left panel, it is the unlensed source, which follows perfect circle Gaussian distribution; In right panel, lensed images is shown, the triangular shape distortion is because of gravitational lensing flexion.

Measuring flexion and calculating the statistical properties with different sizes of window functions.

Use the command below to rebuild Fig. 2.

$ python2.7 wf_selection.py

Figure.2: Figure 2 and Figure 3 in Goldberg et al 2007 can be rebuilt using this python code.