Archive for April, 2008

Item based collaborative filtering in PHP

Most people are familiar with recommendation systems on websites, wherein after you select an item you are presented with a list of similar items other people purchased . Amazon being the popular one and also one of the first to use it. Below is shown a snapshot from Amazon.
Collaborative filtering algorithms work by searching a […]


6 books to master PHP

PHP is a wonderful dynamic language, and the addition of Unicode support, namespaces in the upcoming version 6 will make it even better.
If you are new to PHP or are thinking of moving to PHP form other language then the following list of books will provide you with the required knowledge to become a seasoned […]


Google Pagerank in PHP

Mark Woodman has created a nifty class which lets you query Google pagerank info in PHP 5 and above. The complete classes are available here.
The minimum classes required are ‘cacher.class.php‘ and ‘google_pagerank.class.php‘.
Sample code is shown below.


Time series visualization with Timeplot

Using lines, points and other geometrical objects to visualize data has always fascinated me; specially time series. Time series charts let you visualize data points separated by time intervals.
The following image shows an example of a time series data representing the salary of software engineers for a particular duration.


Faceted browsing for Mozilla Thunderbird

MIT’s Simile project has a new addition to their open source tools, ‘Seek‘. Seek adds a faceted browsing feature for Thunderbird, which lets you search through email or RSS feeds easily.
A faceted classification scheme allows one to assign multiple classes to an object rather then a single predefined taxonomic class. Facets are more commonly used […]