fill area between two curves? fill_between?

The fill() command itself does work if you give it

    > coordinates for a closed polygon. This draws a filled
    > spiral:

Of course (slaps self on forehead). So my example rewritten would be
rewritten using the cleaner

    from matplotlib.matlab import *

    x1 = arange(0, 2, 0.01)
    y1 = sin(2*pi*x1)
    y2 = sin(4*pi*x1) + 2

    # reverse x and y2 so the polygon fills in order
    x = concatenate( (x1,x1[::-1]) )
    y = concatenate( (y1,y2[::-1]) )

    p = fill(x, y, facecolor='g')
    set(p, alpha=0.5)

I took the liberty of adding your example to CVS in the examples
subdir as examples/