Multiple mapping variables leads to overplotting

[cpsievert]

In this example 64 points are plotted, instead of 32.

p <- plot_ly(mtcars, x = disp, y = wt, symbol = factor(vs), color = factor(am), mode = "markers") 
l <- plotly_build(p)
sum(sapply(l$data, function(x) length(x$x)))
#> [1] 64

It'd be awesome if we could extract out the existing infrastructure for ggplotly() which works this way, and take advantage of it in plotly_build().

[cpsievert]

Actually it might be slightly easier/lighter-weight to take advantage of the new groupby transform when it gets merged.

[cpsievert]

Closed via d2bf2a1.