The idea is that the graph can be interpreted intuitively, following the current trend of times where more and more people feel more inclined to interact with graphical content than to read in the old fashion style, anyway, I wrote this explanation where you can find all the icon meanings and the way to understand the lucky/unlucky curve.
As for the way in which the calculations are made, it's long to explain, but basically I used the system of the chinese divination plate, I wrote an article where I explain in detail how I made and use this tool to elaborate the algorithm for this astrological program.
There are many models available of chinese divination plates, this one for example dates back from the Sui Dynasty (581-618 AD):
And here you can see how I use the divination plate I made my self, just put it in front of the computer and use some program that tells the position of the celestial bodies for any given date, it's easy and fun!
The things you see over the divination plate are just to mark the details of the natal chart being used as well as the position of the planets and stars, as you can see I tend to use anything I have at hand, it's just a matter of knowing what are you doing.