Translate ggplot2's color gradients to plotly's colorscale

[cpsievert]

Scatter traces in plotly will now support a colorscale (known as a gradient in ggplot2), so this example:

qplot(data = iris, x = Sepal.Length, y = Petal.Length, color = Petal.Width)

should use a colorscale like this:

[cpsievert]

For future reference, I've been playing with this on #226, and have a working version for plot_ly() which could fairly easily be brought over to ggplotly()

plot_ly(data = iris, x = Sepal.Length, y = Petal.Length, color = Petal.Width, mode = "markers")

(another factor to consider in all this is that discretizing continuous color scales can be perceptually advantageous).

[joshmyzie2]

Has this been partially implemented? I noticed it is working (really well) for geom_tile(), but not geom_point() or geom_line().

[cpsievert]

This should be fixed in f1900cc.