Re: Zero Welch-Stetson Indices found

[Doug Welch <welch@physics.mcmaster.ca>]

John,

Those, of course, aren't *actually* zero - they are rounded to
zero! But, we are "splitting hares" as Bugs Bunny used to warn
against! ;) In any case, I like the code better without the
conditionals, so everyone is happy!

While spending time figuring out the source of the large negative
WS is not completely wasted, so far it has revealed only that the
statistic works the way it was designed to work - photometric
blunders do not end up looking like real variables!

It is always best to be able to prevent bad (cloud/tree/raccoon)
frames from making it into the photometry files when possible. Tom
has rightly pursued the "cloud filter" approach. An additional,
after-the-fact check would be to see which frames cause the largest
net delta WS values when they are reomved from the calculation
of the statistic. Since essentially all the photometry is worthless
on those frames, they should really stand out in such a ranking!

Cheers,
Doug