README

A PHP implementation of the SM-2 algorithm.

About

This is a library created by me to try out popular tools such as Travis, Packagist and Composer, as well as setting up a library structure and enhancing my understanding of test driven development. While being a test project for me, the library is still completely usable and could be used by any database of questions and answers to implement spaced repetition in an application.

Features

• Calculate the interval in which to repeat an item after the n:th repetition based on an E-factor.
• Calculate an E-factor for an item based on the old factor (or no factor) and a response quality.

Installation

Memorize is installed through Composer. Add the following to your composer.json file.

{
    "require": {
    	"wiwofone/memorize": "1.*"
	}
}

The algorithm

SM is a family of algorithms made popular by the SuperMemo software package. The Memorize library implements the complete SM-2 algorithm in PHP. The SM2 class handles calculating repetition intervals and E-factors. The Card class handles flash cards and how many times they have been virtually repeated. Finally, the Repeater class handles actual repetition of a CardQueue, deciding which cards to repeat first and if they have been repeated successfully or not.

Testing

Run PHPUnit with $ phpunit in the root directory.

Author

• Shahin Zarrabi - shahin@wiwo.se - @wiwofone - http://www.wiwo.se