histogram2d with logarithmic z-axis?

[Mattriks]

Yes in Gadfly:

using RDatasets, Gadfly
D = dataset("ggplot2","diamonds")

p = plot(D, x=:Price, y=:Carat,
    Geom.histogram2d(xbincount=15, ybincount=15),
    Scale.color_log10,
    Scale.x_continuous(format=:plain),
    Guide.title("Diamonds")
)