AFit is a RooFit based maximum-likelihood fit toolkit. The purpose of AFit is to add a layer of abstraction to RooFit, so that complicated likelihood models can be constructed using a text file, while at the same time maintaining access to the fundamental RooFit objects that are used in the fit. This package has been developed as a result of many years of analysis experience on BaBar.
In addition to providing utilities to facilitate performing and validating maximum-likelihood fits, there are tools to facilitate plotting the results of the fits, and an interface to the TMVA package. The following lists a few of the features of AFit:
— N-dimensional fit configuration via a text file 'datacard'.
— minimal coding required - the bulk of an analysis is performed using compiled code in a shared library.
— Encapsulation of RooFit PDF classes.
— A a number of additional PDFs have been implemented, such as relativistic BW shapes (and other lineshapes), sigmoid, veto, and step functions.
— The ability to combine 1D PDFs into composites via addition or multiplication. These composites can be combined to form N-dimensional likelihoods.
— Simultaneous PDF building via the AFitMaster class.
— Utilities for plotting and toy MC studies.
— TMVA Interface
— Several examples, including an mes-deltaE fit for a B->VV decay, and a user guide (see below).
— Use RooFit compiled as part of ROOT, or choose to compile against a stand-alone set of RooFit libraries.
AFit was written and is maintained by A. J. Bevan and F. Wilson. Please contact us if you have a question.
This work has been supported by funding from the Royal Society and STFC.This page is maintained by Adrian Bevan.