Tkinter Canvas, spline me!

[Phlip]

Hot Nyp:

Thanks to the group for the answer to my last question here (whatever
it was).

Today we enter a realm where the documentation for the Tk Canvas goes
not.

Ogle this code:

from Tkinter import *
canv = Canvas()
canv.pack()
canv.create_line(  5,  5,  50,  5)
canv.create_line( 50,  5, 100, 50)
canv.create_line(100, 50, 150, 50)
mainloop()

A line with a dog leg in it, right?

I don't want straight lines or angles here. I want a nice smooth
spline that starts at the first point, curves past the middle two, and
ends at the end point.

So I try this:

canv.create_polygon (  5,  5,  50,  5,
                      50,  5, 100, 50,
                     100, 50, 150, 50,
                     splinesteps = 500,
                     smooth = 1 )

That creates a closed polygon - a nasty blob shaped like two filled
triangles pointing at each other. The "smooth" option enables the
"splinesteps" to sand off its corners, but this is hardly the effect I
needed.

Any tips?

-- 
  Phlip                          phlip_cpp at yahoo.com
      http://www.greencheese.org/HoneySatellite
  --  DARE to resist drug-war profiteering  --