[Gnuplot-info] depth in gnuplot?

[Luiz F. C C. <lf...@gm...>]

Hello, I'm new to the List and a new gnuplot user as well. I hope
you don't mind my asking this beginner's question. Here it goes:

I am trying to make a plot of the region in xy-plane bounded by the
curves x=-y^2, x-y=4, y=-1 and y=2. This is what I got so far:


set trange [-1:2]
set xrange [-5:7]
set yrange [-2:3]
unset key
set size 1,1
set origin 0,0
set multiplot
set size 1,1
set origin 0,0
plot 2 lt -1, -1 lt -1, sqrt(-x) lt -1, -sqrt(-x) lt -1, x-4 lt -1
set size 1,1
set origin 0,0
set parametric
plot -t**2, t lt 5 with filledcu y2, t+4, t lt -2 with filledcu y2
unset multiplot
reset


It took me the whole afternoon to come up with this ;)

The problem is I can't see distinctly and completely the lines that
make up the boundary of the region. What be done? is there anything
such as depth as in xfig or is there an easier way to achieve this?
I will appreciate any help.

Thanks, 

Luiz Fernando