PHP number diamond with for loops

forloop.php

<?php
echo "<center>";
$x=30;
// Incremental loop for each horizontal line
for($root=0;$root<=$x;$root++) {

	// Incremental loop (1 till current $root)
	for($inc=1;$inc<$root;$inc++) {
		echo $inc;
		echo " ";
	}

	// Decremental loop (current $root down to 1)
	for($dec=$root;$dec>=1;$dec--) {
		echo $dec;
		echo " ";
	}

	echo "<br>";

}

// Decremental loop for each horizontal line
for($root=$x-1;$root>=1;$root--) {

	// Incremental loop (1 till current $root)
	for($inc=1;$inc<$root;$inc++) {
		echo $inc;
		echo " ";
	}

	// Decremental loop (current $root down to 1)
	for($dec=$root;$dec>=1;$dec--) {
		echo $dec;
		echo " ";
	}

	echo "<br>";
}

?>