<?php
class dewey {
  public $matrix = NULL;
  function __construct() {
    $this->matrix = array();
    for ($i['0'] = '0'; $i['0'] <= '9'; $i['0']++) {
      for ($i['1'] = '0'; $i['1'] <= '9'; $i['1']++) {
        for ($i['2'] = '0'; $i['2'] <= '9'; $i['2']++) {
          $this->matrix[$i['0']][$i['1']][$i['2']] = NULL;
        }
      }
    }
  }
}

$obj['dewey'] = new dewey();

print_r($obj['dewey']->matrix);
?>