blog

Posts Tagged ‘order’

Scoring for Optimization

Friday, April 24th, 2009

Suppose you have a number of competing candidates, each of which can be ranked with a score, but it takes a little time to calculate each candidate’s score. You’re only interested in the top n candidates. You want to come up with a scoring scheme where you can throw the extra candidates out of consideration earlier without sacrificing quality. Such is the problem of scoring and ranking suggestions in Ubiquity. What properties must such a scoring system have?

This blog post includes a lot of complex CSS-formatted graphs which may be best viewed in — what else? — Firefox. You may also want to access this blog post directly rather than through a planet.

candidate 8  
candidate 2  
candidate 9  
candidate 3  
candidate 10 CUTOFF
candidate 5 
candidate 1 
candidate 7 
  

One portion of the problem description above merits clarification: I define “without sacrificing quality” to mean that, if we did not throw out any candidates early and waited until all the scores are computed fully and accurately, we would still yield the same top n winners. This already gives us the key insight towards an appropriate solution: we can only throw out candidates when we know that it has no further chance of making it up into top n candidates.

(more…)

Scoring and Ranking Suggestions

Tuesday, April 7th, 2009

I just spent some time reviewing how Ubiquity currently ranks its suggestions in relation to to Parser The Next Generation so I thought I’d put some of these thoughts down in writing.

The issue of ranking Ubiquity suggestions can be restated as predicting an optimal output given a certain input and various conflicting considerations. Ubiquity (1.8, as of this writing) computes four “scores” for each suggestion:

(more…)

External orders in WordPress queries

Saturday, November 29th, 2008

The advanced WordPress user is intimately familiar with query_posts, the function which controls which posts are displayed in “The Loop.” query_posts gives plugin and theme writers the ability to display only posts written in Janary (query_posts("monthnum=1")) or disallow posts from a certain category (query_posts("cat=-529")1). One of the parameters you can set here is orderby which affects the ordering of the posts returned, with allowed values such as author, date, or title. But what if you want to order your posts in some other order, defined outside of your wp_posts table? Here I’m going to lay out some thoughts on rolling your own external ordering source for WordPress queries.

In order to introduce an external ordering source, we need to do four things: 1. create the external ordering source, 2. hook up (read “join”) the external ordering source 3. make sure we use that order, and 4. make it play nice. ^^

By the way, I’m going to assume you, dear reader, are PHP-savvy, proficient in MySQL, and already know a little about WordPress. This how-to is not for the PHPhobic.

(more…)


  1. This, incidentally, is precisely what I do to hide, by default, my tweets in my index.php and archives.php


© 2006-2010 mitcho (Michael 芳貴 Erlewine).
Proudly powered by WordPress.
Entries (RSS) and Comments (RSS).
The views expressed on these pages are mine alone and do not
reflect those of my employers and clients, past and present.