weird outline with fill


I am using matplotlib 87.4 and I encountered a problem with fill. The outlines
of the filled region look weird when using the TkAgg backend. Same applies when
saved to a png file, so this seems to be a problem of all *Agg backends. The PS
backend is fine. Here is a somewhat longer example, that shows this behaviour.
For comparison, drawing the same outlines with plot gives a perfectly smooth

from pylab import *
x = linspace(0,1, 100)
y1 = x**2
y2 = 1.03*y1
xx = concatenate((x, x[::-1]))
yy = concatenate((y1, y2[::-1]))
fillh = fill(xx, yy, ec = 'k', lw = 0.4)
fillh = fillh[0]
ph = plot(x, y1+0.1, 'k-',
     x, y2+0.1, 'k-', lw = 0.4)
savefig('jaggyfill.png', dpi = 150)

The more points I use, the worse the result. I create a png file since I need
alpha filling, eps doesn't support this. Creating a high resolution png and
downscaling improves the result, but this is tedious and time consuming. Any
help is appreciated!

Thanks in advance

Gregor Thalhammer

PS. Is this the right place to discuss such problems?