scatterplot with alpha transparent histograms in R

Question

How can scatter plots with alpha transparent, scale-less histograms can be made in R, like this figure?

looks like it\'s not made in ggplot2.

Answer 1

I have no idea whether there is a package that does that directly, but I'm sure this can be done in R. Transparency is easy: you add another two digits to the RGB specification of a color for a given transparency:

#FF0000 # red
#FF0000FF # full opacity
#FF000000 # full transparency

Combining different plots is also easy using the layout function. As for the vertical density plot, it is just the same as the horizontal plot with x and y switched. The example given here can easily be expanded to include colors, smaller margins etc. I can try to come up with a more elaborate example if this description is not sufficient.