[Bug 865378] Add support for multiple Y axises.

[mythmon]

This uses "axis groups". Each axis group's maximum is calculated, and then the entire group is scaled so that the maximum is 1.0. Then the axises and the hover tool tips are adjusted to show the correct numbers. The scaling is adjusted as the zoom is changed and as axises are toggled on and off. I updated the question stats graph to make use of these features

• initData and makeSeries modified to calculate scales for each axis group, and use them when drawing.
• Wrote a custom y axis class that makes room for itself around the graph, inserts itself, and supports being added multiple times. It also sets its scale based on a parameter instead of of data (since the data is just from 0 to 1 now).
• Added a new Hover class, making it respect the scale of series as well, so that the hover tool tips show the original values. I also made the BarHover class an extension of this, for DRYness.

r?

This is kind of hacky, and the more I do this, the more I want to just use d3 directly.

[mythmon]

Divs like this are automatically added now.

[rlr]

at some point I thought you had all these divs added from js?

[mythmon]

Not all of them, just some. I tried to do all of them, but ran into some issues and decided not to spend more time on it.

[mythmon]

Oh, and now you can turn multiple sets on and off, with the assumption that they are different axis groups. ie: They are checkboxes instead of radio buttons.

[rlr]

so this sets the max of the axis group to the max of all the series' maxes?

[mythmon]

Yes. I'll add a comment, but can you think of a cleaner way to do this?

[rlr]

You can use _.max. I think something like:

_.max(this.data.series, function(series){ return series.max; });

That should replace this entire for loop?

[mythmon]

Not quite, since this is grouping by the name of the axisGroup. Leaving it for now.

[rlr]

This is intense! I can't see it in action yet, can I?

[mythmon]

You can see it in action! Check out the history charts, like at /kb/private-browsing-browse-web-without-saving-info/history. The percents and the votes use a different scale.

[mythmon]

Alphabetized CSS based on feedback ^

[rlr]

yay it worked! let's and move to the next one. r+

[mythmon]

8da5686