geom_density() as filled area chart

[cpsievert]

See #199.

[cpsievert]

New tests --

http://ropensci.github.io/plotly-test-table/tables/4659669a2ea26bb8537cfc70b6e714afd6f62094/density-simple.html

http://ropensci.github.io/plotly-test-table/tables/4659669a2ea26bb8537cfc70b6e714afd6f62094/density-fill.html

http://ropensci.github.io/plotly-test-table/tables/4659669a2ea26bb8537cfc70b6e714afd6f62094/density-color.html

Something strange is happening with the density-fill example. If I click on "fork and edit", it takes me to another page that renders the plot correctly

Could this be some sort of bug with plotly itself @chriddyp @mkcor ?

[tdhock]

Nice tests, and yeah that it weird about the difference between the rendered plotlys.

@alexcjohnson do you have any idea why this same plotly is rendered differently in these two cases?

[cpsievert]

I don't think I can do anything to fix the problem above, so I'd prefer to merge, then post that rendering issue somewhere more appropriate. Any ideas on where that might be @chriddyp @mkcor @tdhock?

Please review and +1 when you get a chance.

[alexcjohnson]

Ah, apologies for not looking at this before. I just did tried "fork and edit" and didn't see a change... but I can imagine where it could come from. The issue is the null at the end of the x array in the first trace. You're right that this shouldn't break it like this, so I'll open an issue for it on the plotly side - but I also imagine it's not quite what you had in mind here...

[cpsievert]

Nice, thanks for catching this @alexcjohnson!

I'll push a fix shortly.

[cpsievert]

Everything looks good now!

http://ropensci.github.io/plotly-test-table/tables/4a336c65d8cdc0a4f974912a4e93d45e1852e003/index.html

[mkcor]

Space after closing ).

[mkcor]

Nice work, @cpsievert !
I only spotted a missing whitespace. Up to that, that's a +1 from me.