A utility class to allow the calculation of the chisq of the fit to the Dalitz plot.
A text config file is provided that gives the datasets for the data and
toy MC generated from the fit results. These can be in the traditional DP
or the square DP. A sample config file is provided. The fields are:
<name of file containing data histogram> <name of data tree> <name of the x axis variable in data> <name of the y axis variable in data>
<name of file containing toy MC histogram> <name of toy MC tree> <name of the x axis variable in toy MC> <name of the y axis variable in toy MC>
<the minimum content for any bin> <the number of free parameter in the fit> <the scalefactor by which the toy MC bin content should be multiplied> <minimum x value> <maximum x value> <minimum y value> <maximum y value>