Re: Focus indication

[Andrew Bennett <andrew.bennett@ns.sympatico.ca>]

On Thu, 2 Aug 2001 12:27:49 -0600 , "Creager, Robert S"
<CreagRS@LOUISVILLE.STORTEK.COM> wrote:

>...
>Andrew, are you then interpolating with 3rd order splines, since the 4th
>order was too painful?
Oops! I've been spending too much time with the
vines! When I said "4th order" I meant "4 point"
i.e. cubic splines. These are already quite pathological
enough with real world noisy data!!

I abandoned interpolation altogether. Each attempted
fit is computed at the data points from the formula,
whatever it is today, and then compared with the data.

Using any kind of interpolation beyond linear, I was
unable to avoid little nasties such as exp(real) =
negative.

Andrew Bennett, Avondale Vineyard