How to make a circular density/contour plot with gnuplot

Question

I wish to show a plot in which each radius represent a colour. So I have set of radii and the density for each radius like this:

#radius #density
1     0.9
1.5   0.8
2     0.6
2.5   0.4
.... many more

I know how to plot one radius but how I can plot in some sort of circular(radial) density/contour like plot?

Answer 1

Here is one possibility: Thats draws overlapping circles, which are coloured according to the current palette definition. For this to work, the data must be sorted with descending radius values, which is done here on-the-fly using the sort Unix command line tool:

set palette defined (0 'white', 1 'blue')
set cbrange [0:1]
unset key
plot '< sort -r data.dat' using (0):(0):1:2 with circles lc palette fillstyle solid noborder, \
     '' using (0):(0):1:($2+0.1) with circles lc palette lw 3