Thursday, March 08, 2007

One Step Forward

Two steps back.

I figured out something in my dissertation this morning, but it means undoing some of the stuff I had been doing. Not much, thankfully, but it's annoying nonetheless. I had been using an "in-order tree ordering" for something, but then decided an ordering based on Gray codes was closer to being optimal in efficiency. However, it turns out that the Gray code order messes up a property I was depending on in the tree order, and that drastically affects the difficulty of deleting bonds... and thus messes up the small amount of efficiency that Gray codes added. (And I think makes them considerably worse.)

So now I get to re-write two sections of my dissertation. In a way, I'm kind of glad I hadn't gotten around to implementing that part yet. ;)

This was a rather satisfying discovery... it helps with the gloomy mood a bit in a vindictive kind of way. Which isn't nice of me. But it's also kind of self-affirming... that I *can* make a contribution.

(Yes, I know this sounds like a bunch of gobble-de-gook. Please ignore this post if it does.)

3 comments:

Deneen said...

Yes, it's truly gobble-de-gook, however I'll use this opportunity to let you know I did ship your package today, airmail-I guess a week or so.

Suzanne said...

So what you're saying is... Using Gray Codes instead of binary trees, traversal is faster. The unstated implication is that the "academic community" has long realized this. But what the DIDN'T realize -- and what you've just figured out -- is that deletion is much slower. Hah!

This realization satisfies you greatly. Another hole poked in the uppety linens of Computational Geometry. To be patched by NORICUM'S crocheting hands.

Hole #1,297 patched: Just another day in the work of the Computational-Crocheting Avenger. But this one is earmarked for mass distribution.

Is this somewhat how the story goes? ;)

I had way too much fun with that. :P I don't really know what you're talking about. But I know it brings a small vindictive happyness of the Ph.D. kind, so congrats!!

--suzgames79 / nazzus on LJ
(sorry, forgot my damned password here)

noricum said...

Eh, you make it sound more important than it actually is. Gray code ordering has fewer bit flips, but for my particular application, trees are the way to go. ;)