Add hive plot to networkD3

[cashoes]

This is a minimal working implementation of the hive plot (http://www.hiveplot.net/) largely adapted from code by Mike Bostock found here (https://gist.github.com/mbostock/2066415).

Currently maps nodes to 3 axes by identifying sources, sinks and hub or manager nodes. Node size, colour, link size and colour are mappable, though I still need to add some sanity checking code on the R side to make sure inputs make sense.

I'd appreciate a discussion around features to add or tips on the javascript side, as this is my first dive into D3.js.

[timelyportfolio]

I look forward to checking this out. I had built d3hiveR(blog post). Maybe we can merge the two for functionality. In this little bit of code, I sort of discuss what I was trying to accomplish.

[cashoes]

My googling-skills failed me... I knew of HiveR, but wasn't aware of d3hiver (when do you sleep?!) The functionality of mine is pretty basic (I took this on partly to learn more about D3). Thank you for the blog post link... I'll take a look. Merging functionality seems the best path forwards and leveraging HiveR's existing capabilities would be smart...

[timelyportfolio]

@cashoes, blame it on my complete disregard for SEO :) Let me know what you find and let's make it better. I know networkD3 is particularly focused on simplicity and universality, so if we get too specific or complicated then perhaps we should target a dedicated, focused package.

[christophergandrud]

This looks interesting. @cashoes could you provide a minimally working example for the hiveNetwork documentation and testing?

[cashoes]

Sure thing @christophergandrud! Any chance you could provide an example of the type of testing you have in place for existing networkD3 functions? e.g. do you write tests just on R side? Or for the JS as well?

[christophergandrud]

Currently there are just test in R that should trigger a variety of behaviours in the JS. Kind of simple.