[Ifeffit] Re: sigma squared

[Matt Newville]

Carlo,

> The screenshot did not come through to me but I can tell you
> what I have discovered for the Kaiser-Bessel function:
> 
> 1. in Chi(k) the window starts to drop at the selected value.  
> It reaches zero a bit lower (higher) than the value set.  In
> k-space, it is hard to see this because of the scale but if
> you zoom, you can see that the drop takes about 0.05 delta k.  
> See the "k-space.png" attachment where the window is set to
> 2.997.

It's probably that 0.05Ang^-1 is the spacing between points in
k-space, so you're just seeing the line that join two successive
points.  The danger of looking too closely!

--Matt