A picture is worth a thousand words. This is true both for photographs and for graphs, but sometimes the words are spoken to the wrong ears. I would like to offer you a very simple, visual test today: show you a picture and let you guess what it represents. Depending on the response, this might end in oblivion or be tried again with another subject.
So the question is: what does the picture below represent ?

A few hints:
- I did the graph myself, and it took me 10' of programming and a tenth of a second of CPU on my laptop.