tappy.php

<?php
class Rhythm {
	var $length, $duration, $_prevTap, $_curTap, $_taps, $_weight;
	function __construct($length = 0, $duration = 0, $_taps = array(), $_weight = 1) {
		$this->length = $length;
		$this->duration = $duration;
		$this->_taps = $_taps;
		$this->_weight = $_weight;
	}
}

function compare($r1, $r2, $inelastic) {
	var $error, $multiplier, $length, $dur1, $dur2, $rHi, $rLo;
	if (is_numeric($r1->_tap) || is_numeric($r2->_tap)) {
		throw new Exception('Can\'t compare Rhythms before calling done()');
	}
	$length = count($r1);
	if ($length !== count($r2)) {
		return false;
	}
	$length--;
	$r1 = $r1->_taps;
	$r2 = $r2->_taps;
	if (!$inelastic) {
		function sum($acc, $tap) {
			return $acc + $tap;
		}

		$dur1 = array_reduce($r1, "sum");
		$dur2 = array_reduce($r2, "sum");

		if ($dur1 > $dur2) {
			$rHi = $r1;
			$rLo = $r2;
		} else {
			$rHi = $r2;
			$rLo = $r1;
		}

		$multiplier = array_reduce(array_map(
				function($tHi, $i) { return $rLo[$i] / $tHi; },
				$rHi,
				array_keys($rHi)
			), "sum") / $length;

		$rHi = array_map(function($tap) { return $tap * $multiplier; }, $rHi)
	} else {
		$rHi = $r1;
		$rLo = $r2;
	}
	return 1 - array_reduce($rHi,
		function($acc, $tap1, $i) {
			$tap2 = $rLo[$i];
			$tHi = max($tap1, $tap2);
			$tLo = min($tap1, $tap2);
			return $acc + $tHi - $tLo / $tHi;
		}, array_keys($rHi)) / $length;
}
?>