Implementing Bayesian inference using PHP: Part 1, IBM developerWorks, March 2004.

Conditional probability -- the probability of observing one event given that you have observed another event -- is a potentially important factor in designing intelligent Web applications. Paul Meagher introduces Bayesian inference by discussing the basic mathematical concepts involved and demonstrating how to implement the underlying conditional probability calculations using PHP. In this article, the author discusses how Bayesian inference can be used to build an online PHP-based wizard that guides a user through the process making a medical diagnosis. This three-part series features interesting applications designed to help you appreciate the power and potential of Bayesian inference concepts.

Last updated: Feb 27, 2004 - 4:30 PM AST

Demos:

• getConditionalProbability.php - frequency-based method for computing conditional probability using smoking and cancer example
• test_bayes.php - compare to Grinstead & Snell, Introduction to Probability, p. 147
• bayes_wizard.php - the featured Web application

• getConditionalProbability.php
• Bayes
• test_bayes.php
• bayes_wizard.php
• bayes_wizard_step1.php
• bayes_wizard_step2.php
• bayes_wizard_step3.php
• bayes_wizard_step4.php
• bayes_wizard_step5.php
• index.php