Fitting data with Python

Fitting models to data is one of the key steps in scientific work. Some examples are:

• fitting some spectrum/spectral line
• fitting 2D light distribution of a galaxy
• fitting orbits of exoplanets
• estimating the galaxy luminosity function from data

Numpy and Scipy provide readily usable tools to fit models to data. Moreover, Python is an excellent environment to develop your own fitting routines for more advanced problems.

Goals of this session

• How to use implemented routines: leastsq and curve_fit.
• Astrophysical example: Salpeter mass function.
• MCMC using emcee the MCMC Hammer

Agenda

• Introduction
• Least-squares fitting in Python
• 1D Examples and Exercise
• Fitting a spectrum with Blackbody curves

Authors:Eli Bressert, Rene Andrea & Neil Crighton Copyright:2012, Eli Bressert, Rene Andrae & Neil Crighton