Detects the gender (male or female) of a name

gender.php

<?php

/**
 * returns positive if male, negative if female
 */
function gender( $s )
{
	$gender = 0; // female - , + male
	
	$letters = array(
		'a' => -5.652604738,
		'b' => 0.4848823163,
		'c' => 0.5988183031,
		'd' => 1.710755277,
		'e' => -1.615090236,
		'f' => 0.6095456877,
		'g' => 0.4637426344,
		'h' => 0.1492751921,
		'i' => -2.95725719,
		'j' => 0.3618602821,
		'k' => 0.4110798047,
		'l' => -1.93138848,
		'm' => -0.2297501411,
		'n' => 0.6760146965,
		'o' => 3.312554183,
		'p' => 0.005272049275,
		'q' => 0.03719266012,
		'r' => 2.029755446,
		's' => -0.06039585511,
		't' => 0.4342335742,
		'u' => 0.8660267662,
		'v' => 0.3174885737,
		'w' => 0.5574388945,
		'x' => 0.1022798153,
		'y' => -0.5130651266,
		'z' => -0.1686643889,
	);

	$chars = count_chars( strtolower( $s ), 1 );

	foreach ($chars as $char => $times)
	{
			$gender = $gender + ($letters[ chr($char) ] * $times);
	}

	$gender = $gender + $letters[ substr($s, -1, 1) ] * 5;

	
	return $gender;
}

echo gender('John');