Geom.contour in Gadfly.jl - How to use it?

Specific Domains Visualization
3

The above example should work (because z is a function), but the issue is the Inf values on the edges of the domain (which I assume cause a problem for Contour.jl).

plot(z=(x,y) -> negLogDensFun(x,y), Geom.contour(),
         xmin=[0.001], xmax=[0.999], ymin=[0.001], ymax=[10^4.9], 
    Theme(line_width=3pt)
    )

Contour