Porcine Joy

Opening measures from The Rite of Spring

Spring showers bring pig flowers.

Well, maybe not. But I haven’t featured any pigs recently. That could be in violation of the “Ellie Asks Why” site charter. The Ides of March are past, and we head into spring. We also approach the one-year anniversary of this blog on March 21 or thereabouts, right in time for the vernal equinox. I would like to take this opportunity to thank my loyal subscribers, all three or four of you. And my occasional and less occasional readers. Please note the recent inclusion of two blogs on the Blogroll on the lower right side of the page, The Adventures of Benny and Neal Reed Virtual Support. Both have included this blog on their websites link lists/ blogrolls. I, in turn, was completely oblivious for many months, to my chagrin. Also making an appearance for the first time is my own hobby blog, In the GooglePlex, whose URL was carefully selected so as to avoid any concerns of trademark infringement with its namesake. This will probably alert the horde of former Soviet-bloc country pharma spammers who regularly deposit their calling cards as comments here.  In the GooglePlex will no doubt experience a deluge of Acai Berry Diet and Cialis-Levitra-Viagra spam, yet there is no help for that. Finally, a nod of acknowledgment to the true experts in my field of expertise, Data Quality (“DQ”), as well as statistical commentary and very wry humor . I’ll recommend some of the more whimsical entries from my favorite DQ sites:

• Obsessive-Compulsive Data Quality Blog: OCDQ
• Lilienthal on Data Quality
• Eager Eyes
• and

Any Rite of Spring Should Include an Oink of Joy

With thanks to http://twitter.com/#!/TruthSandwich/status/36112729433444353 for this.

Economic Models for Turbulent Times Part I

Consider Crust

Strange topology at MIT

Crust is an algorithm for reconstructing surfaces of any topology. In other words, it is a method for digitally rendering any 3-D shape, using data in three-dimensional space as input. Such methods garner a lot of attention now a-days. Graphical simulation models are increasingly prominent for visualization and testing purposes in the field of particle physics. World of Warcraft and Second Life rely heavily on computationally intensive computer graphics, and scalable distributed systems in general. Perhaps the most complex system of all is the U.S. economy, whose governance is partly guided by the results of mathematical models as part of monetary policy and fiscal planning.

Crust was developed as a collaborative effort between two staff scientists at Xerox PARC, now known as Palo Alto Research Center, and a doctoral candidate at MIT. None of this happened recently. In fact, Crust hasn’t been semantically linked with the word “new” since its debut at the 1998 ACM SIGGRAPH Conference.

What is so special about Crust? How is it relevant to global central banks and economic policy officials? What about the Federal Reserve Bank? Patience, please. Tarry a bit longer with me. All will be revealed.

The Crust algorithm is special because it has certain features uncommon in most quantitative models, yet highly sought after. First, the Crust algorithm offers results with “provable” guarantees. Given a “good sample” from a smooth surface, Crust’s results are guaranteed. That is, Crust guarantees that its output is topologically correct, converging to the original surface with increasing faithfulness depending on the input data’s sampling density.

Graphical Computation using the Crust Algorithm: An MIT PIG-tacular!

Crust has another interesting feature. The Crust research team was aware of how difficult it was to accurately model real world phenomena. They express such sentiments in their peer-reviewed academic publications. At least one was unusually receptive to the shortcomings of  mathematical models,  due to random events and interactions in the wild, e.g. unexpected co-linearity. Manolis Kamvysellis did much of the implementation and testing work on the Crust project. He was the third member of the team, studying for his Ph.D. at MIT. Happily, he had the good sense to demonstrate the algorithm via this fine pink pig! Let’s do the same.

Recall that Crust’s criteria for acceptable sample density is dynamic. Sample size is surprisingly intuitive! It depends on how dense the available data points are. A single topological surface, such as Piggy, may have very detailed surfaces. Observe this near Piggy’s ears and snout. Other areas like the hindquarters are quite featureless. Yet Crust dynamically adjusts its smallest acceptable sample size accordingly. Even minimally detailed surfaces such as Piggy’s lower hind legs above the hooves can be reconstructed accurately.

Manolis wrote a short-form version of the original ACM journal publication: A New Voroni Based Reconstruction Algorithm, click to download as a pdf file.  Google Chrome browser users may save directly to Google Docs, an option built into yesterday’s Chrome version 8.xxxx update.

To Be Continued….

Check back for Part 2 of Economic Models for Turbulent Times

Learn how and why crusty old Crust is relevant to the 2007 – 2010 economic and global financial crisis, and how it might be helpful going forward in 2011.

Nat’s Little Piggy

Originally uploaded by Nat Nunn Nat says:

This little piglet is only about a week old. They were really scared when I first went in but after a while some came closer to me.

Racing Pigs

The Crowd Goes Wild: They're Off!

A startling issue was recently brought to my attention. This blog has had mighty little to do with pigs recently. I seem to recall that periodic coverage of matters of a piggy sort was a stated objective of the Ellie Asks Why blog- pen charter.

Good news: The dry spell is over!

She's Graceful and Fleet-of-Hoof!

Feast your eyes on a parade of racing Oinkers from the 2008 Annual Pig Races of Melbourne, Australia.

A brief selection of  pearls amongst swine will round out today’s long overdue porcine themed post.

Snout-to-Snout Photo Finish