Re: [PyX-devel] Re: "smoothed" attribute in PyX

[Michael S. <m-s...@us...>]

Hello Peter and André,

On 06.12.04, Andre Wobst wrote:
> > Finally, the diagrams have wiggly lines (roughly sinusoidal) attached 
> > at either end to represent the velocity operator. It would be great if 
> > there were a "deformer" which give a wiggly line instead of a cycloid. 
> > Are there plans to extend the "deformer" functions in the future?

Please note that lots of "wiggly" lines can be thought of. A cycloid
might look like a sinusoidally wiggled curve if you stretch it
tremendously. A precise sinus is something different, however.

The main problem with deformers that try to implement a well-defined
geometrical thing like a cycloid or a sinus is how to cope with the
curvature of the underlying curve. This is something I tried to
optimize in the cycloid, and which makes it quite hard to understand
(I guess).

More deformers with sinus, zig-zag, ... would be nice.

> There's another thing worth some thoughts in the design phase of such
> a "framework" for feynman diagrams. Stroking arrows at the paths (at
> the end or in the middle of a path) should be straight forward. Such
> an arrow would be a decorator, not a deformer, by the way. But what I
> would take care of from the very beginning are those double lines. I'm
> not totally sure how those should be created starting from a
> connecting path in the beginning. Should we start to have two paths
> for that case. I don't think so ... but I do not have strong arguments
> at hand.

Do you mean to parallel curves with constant distance to each other?
You certainly remember our discussion on the problem of "extending"
curved boxes this way. This is, again, the same problem -- and it is a
hard one.

Michael.

-- 
"A mathematician is a device for turning coffee into theorems"
  Paul Erdös.