The code uses two approaches to fit the experimental data with gamma distribution .

1. find a0 + a2P2 + a4P4, then use a0 to search for mini delta, the mixing ratio
2. fit the a0, delta, and sigma simultaniously.

simply make to compile the ad++.cpp

The settings and data are hard coded.

or, using root, load ad++.h as macro

for mac user, please use d71f18d branch