« June 2007 | Main | September 2007 »

August 2007 Archives

August 31, 2007

The Limits of Search

An interesting perspective on generalized search, with an informal but convincing conjecture on fundamental limitations to search problems. (In a word, TANSTAAFL.) To wit:

If you’re going to find a needle in a haystack, then you’ve got to expend at least some computational effort sifting through the hay.

The author ties it in with computational complexity theory and the age-old question of whether P = NP:

Many people — even computer scientists — don’t appreciate just how profound the consequences would be if P=NP. They think it’s about scheduling airline flights better, or packing more boxes in your truck. Of course, it is about those things — but the point is that you can have a set of boxes such that if you could pack them into your truck, then you would also have proved the Riemann Hypothesis!

He postulates that these fundamental limitations constrain not only classical but also quantum computing, railing against the modern conception of quantum computers as generalized massively parallel solvers. All in all, quite an interesting perspective. Nothing fundamentally profound or groundbreaking here, but it all makes sense.

August 30, 2007

Ambition

Ambition by Chris Wanstrath is not only the coolest thing in Ruby since ruby-inline, it is also one of the best examples of practical functional programming that I have ever seen. Go check it out and be enlightened.

August 25, 2007

Metric Spaces

Fascinating paper on vp-trees, useful for generalized BSP indexing over metric spaces. Like a kd-tree but more flexible and abstract, and more useful on non-Euclidean distance metrics. I've been thinking about using vp-trees over a Levenshtein-distance metric space for some code complexity assessments--seems to have better performance than either a kd-tree, and more generality than a bk-tree.

About August 2007

This page contains all entries posted to Brad Ediger in August 2007. They are listed from oldest to newest.

June 2007 is the previous archive.

September 2007 is the next archive.

Many more can be found on the main index page or by looking through the archives.