Changing color along the line of a 2D plot

[Martin Kretschmar]

Hello everyone,

i would like to plot a 2D graph, e.g. a gaussian profile, in gnuplot with a changing color along its line.
The result should look similar to this example:

http://www.physics.unr.edu/ntf/images/laser2.jpg

In one example, i would like to have the colorgradient along the 2d line, in the other example i would like it to look similar to the linked image, which means with filledlines or s.th. similar.

Thanks in advance for your support.

Cheers

[Ethan Merritt]

gradient along line:
plot $foo using 1:(f($1)):(color($1)) with lines lc variable

gradient fill:
not possible in gnuplot