protovis part 2: lines and labels
So lets take a look at the tick lines data. It would be very time consuming if you had to manually type in where you wanted your lines. Protovis has a method that makes it much easier.
Delete the data array and and replace it with pv.range. In parenthesis, type 0 for the start point, type 2 for the end point and type .5 for the increment. This is really helpful when working with larger numbers.