Tau statistics

[martinkilbinger]

Implement and run tau statistics.

These are a generalisation of the rho statistics (Rowe 2010, Jarvis et al. 2016). Three parameters need to be fit
to observed galaxy - PSF cross-correlations. Using the best-fit values, a correction can be applied to the shear-shear correlation function.

Implementation into sp_validation or https://github.com/martinkilbinger/shear_psf_leakage .

• Measure cross-correlations
• Compute covariance matrix
• Fit parameters
• Create plots
• Quantify and apply correction