Multiple Axes for a Graph

Let’s imagine that we want to show our wonderful graph with two lines, much like we already have, but imagine that the data that the lines are made from is significantly different in magnitude from the original data (in the example below, the data for the second line has been reduced by approximately a factor of 10 from our original data).

date,close,open
1-May-12,58.13,3.41
30-Apr-12,53.98,4.55
27-Apr-12,67.00,6.78
...

Now, this isn’t a problem in itself. D3 will still make a reasonable graph of the data. But because of the difference in range, the detail of the second line will be lost.