[AstroPy] Transit light curve functions

[Ian Crossfield]

Being unable to find a Python compilation of the analytic transit light 
curve formulae from Mandel & Agol (2002), I have created one myself, 
documented here: http://astro.ucla.edu/~ianc/python/transit.html .  It 
contains expressions for all cases treated in the original paper: 
uniform-disk, quadratic limb-darkening, full (4-parameter) 
limb-darkening, and the quick, small-planet approximation.

Written in Python, these routines are a factor of 5-10 slower than the 
corresponding IDL versions, and perhaps slower still than an 
implementation in Fortran (as available from Eric Agol's website: 
http://www.astro.washington.edu/users/agol/ ).  Nonetheless, I hope that 
someone may find them useful.  If you do, please feel free to use them 
or adapt them to suit your own needs.

And as always, if you find a bug please let me know.

-- 
Ian Crossfield
UCLA Astronomy
KH 3-145J
http://www.astro.ucla.edu/~ianc/