The link you gave actually has 20,000 points of data on that graph. The example is interactive so go ahead and change line 45 or line 65 to something bigger then click the green button if you want to see a bigger data set. I love how their examples are interactive right on the page.
I see no interactivity there. The mouse only shows the x and y coordinates. As I said, I am looking for examples where the data is manipulated. Mouse over that shows data values would also be interesting though.