Centered axis

[parikhshiv]

Add new centeredAxis option for y-axis - focus is on dynamically centering y axis around data. Unlike default axis scaling, this option ignores the zeroAnchor option (meaning that the y axis will not be anchored at zero by default).

This PR also includes the changes from branch y-axis-scaling.

Here is a jsfiddle that illustrates the use of the centeredAxis option - http://jsfiddle.net/a5L7x0c5/1/

[narenranjit]

@parikhshiv
Can you comment on the new options added? This'll then need to be assigned to molly for documentation purposes.

Also, as a general rule of thumb, don't close your own prs ;)

[parikhshiv]

Sure @narenranjit (and noted in terms of future PRs) -

Basic idea of the centered axis is to vertically center the y axis around data points.

An updated example of use of the centered axis can be seen here - http://jsfiddle.net/a5L7x0c5/3/ (also demonstrates new placement of zeroAnchor and smartAxis flags).

All changes are backwards compatible (tested), but we may want to update docs re: formatting of yAxis options with the new 'scaling' attribute.

[mmrj]

@parikhshiv thanks! on my list to review, but behind 2 x epicenterjs releases ... will let you know as i have questions.

[narenranjit]

Moving those options to 'scaling' is a start, but aren't some of those options contradictory? i.e scaling: { smartAxis: true, centeredAxis: true } will never makes sense/work; it'll always be one or the other.

Rather than just updating the docs saying "don't use both", a good API should prevent them from doing both if at all possible. One way to do this is to change the above line to read scaling{ type<String>:"smart or centered or ...", options: <any further config options required by the scaling algorithm, like the zeroanchor> } ; this'll make it impossible to turn on both smart and centered at the same time.

Another advantage of doing it this way is it reduces the testing surface area. i.e, rather than write a different test case for "smart:true, center:true" "smart: true, center: false" and all the other permutations, you just write 1 per config options.

Let me know if this makes sense, or if i misunderstood how those options work (entirely possible).

[parikhshiv]

No, this makes sense to me @narenranjit - I can update the structure of the scaling option according to what you've specified above.

This may take a few days (just a heads up in terms of updating docs, @mmrj ).