MarkovModelCode

<?php
 
class MarkovFirstOrder {
 
        private $hash;
 
        public function __construct() {
                $this->hash = array();
        }
 
        /**
         * Adds a new word and the word following it to the model (first order)
         * @param word
         * @param next
         */
        public function add($word, $next) {
                // first, does the word already exist?
                if (isset($this->hash[$word])) {
                        $this->hash[$word][$next] = (isset($this->hash[$word][$next]) ?
                                                        $this->hash[$word][$next] + 1 :
                                                        1);
                } else {
                        $this->hash[$word] = array();
                        $this->hash[$word][$next] = 1;
                }
        }
 
        public function debug() {
                print_r($this->hash);
        }
 
        /**
         * Returns the next word from the distribution, given the current word.
         * @param word
         * @return
         */
        public function get($word) {
                // first, does the word even exist?
                if (!isset($this->hash[$word])) {
                        return '';
                }
                $subarr = $this->hash[$word];
 
                // w00t
                // calculate the sum of the counts of the next possibilities
                $sum = 0;
                foreach ($subarr as $count) {
                        $sum += $count;
                }
 
                // generate a random number in this range
                $rand = mt_rand(1, $sum);
 
                // loop again, this time stopping once the counts have
                // reached the random number we generated, then return
                // that word
                $sum = 0;
                foreach ($subarr as $w => $count) {
                        $sum += $count;
                        if ($sum >= $rand) {
                                return $w;
                        }
                }
        }
}
 
?>