- print_r: documentation ( source)
<?php
$data[0][1]['tot_km'] = array(array("0" => 52, "1" => 23), array('tot_km' => Array('0' => 46)));
$data[1][1] = array('tot_km' => array('0' => 38, '1' => 22, '2' => 40));
$data[1][2] = array('tot_km' => array('0' => -395, '1' => 28));
print_r($data);