helper functions

index.php

<?php

require_once('./xpto.php');

Dump(get_loaded_extensions(false));

die();

$xref = array
(
	'a' => array(),
	'b' => array('a'),
	'c' => array('a', 'b'),
	'd' => array('a'),
);

Dump(Export('$xref', $xref));

// START OF PARENTESCO

function Parentesco($h, $refs)
{
	$result = array();

	if (array_key_exists($h, $refs) === true)
	{
		$result = array_fill_keys(array_keys($refs), 0); // iniciar tudo a 0

		foreach ($refs as $n => $n_refs) // para cada outro texto n
		{
			if (strcmp($h, $n) === 0)
			{
				$result[$n] = -1; // para si mesmo o parentesco é -1
			}

			else
			{
				if (in_array($h, $n_refs) === true) // h é usado como referencia em n?
				{
					$result[$n] += 1;
				}

				else if (in_array($n, $refs[$h]) === true) // ou vice-versa?
				{
					$result[$n] += 1;
				}

				//$result[$n] += count(array_intersect($n_refs, $refs[$h])); // numero de referencias comuns entre h e n
			}
		}
	}

	return $result;
}

$parentesco = array();

foreach (array_keys($xref) as $h)
{
	$parentesco[$h] = Parentesco($h, $xref);
}

Dump(Export('$parentesco', $parentesco));

// END OF PARENTESCO (why / where will this be used?)

class Stelaro
{
	public static function Delve($key, $data, $depth = 0)
	{
		while (--$depth >= 0)
		{
			$key = Flatten(array_intersect_key($data, array_flip((array) $key)));
		}

		return array_intersect_key($data, array_flip((array) $key));
	}

	public static function Ranking($doi, $references, $depth = 0)
	{
	}
}

// START OF PROFUNDIDADE

for ($i = 0; $i <= 5; ++$i)
{
	Dump(sprintf('Referencias de %sC (%u)', str_repeat('referencias de ', $i), $i), Stelaro::Delve('c', $xref, $i));
}

// END OF PROFUNDIDADE

function calculatePageRank($linkGraph, $dampingFactor = 0.15) {
        $pageRank = array();
        $tempRank = array();
        $nodeCount = count($linkGraph);

        // initialise the PR as 1/n
        foreach($linkGraph as $node => $outbound) {
                $pageRank[$node] = 1/$nodeCount;
                $tempRank[$node] = 0;
        }

        $change = 1;
        $i = 0;
        while($change > 0.00005 && $i < 100) {
                $change = 0;
                $i++;

                // distribute the PR of each page
                foreach($linkGraph as $node => $outbound) {
                        $outboundCount = count($outbound);
                        foreach($outbound as $link) {
                                $tempRank[$link] += $pageRank[$node] / $outboundCount;
                        }
                }

                $total = 0;
                // calculate the new PR using the damping factor
                foreach($linkGraph as $node => $outbound) {
                        $tempRank[$node]  = ($dampingFactor / $nodeCount)
                                                + (1-$dampingFactor) * $tempRank[$node];
                        $change += abs($pageRank[$node] - $tempRank[$node]);
                        $pageRank[$node] = $tempRank[$node];
                        $tempRank[$node] = 0;
                        $total += $pageRank[$node];
                }

                // Normalise the page ranks so it's all a proportion 0-1
                foreach($pageRank as $node => $score) {
                       $pageRank[$node] /= $total;
                }
        }

        return $pageRank;
}

Dump(calculatePageRank($xref));

?>

xpto.php

<?php

function Dump()
{
	static $i = 0;

	foreach (func_get_args() as $argument)
	{
		if (is_resource($argument) === true)
		{
			$result = sprintf('%s (#%u)', get_resource_type($argument), $argument);
		}

		else if ((is_array($argument) === true) || (is_object($argument) === true))
		{
			$result = rtrim(print_r($argument, true));
		}

		else
		{
			$result = stripslashes(preg_replace("~^'|'$~", '', var_export($argument, true)));
		}

		if (strncmp('cli', PHP_SAPI, 3) !== 0)
		{
			$result = sprintf('<pre style="background: #%s; margin: 5px; padding: 5px; text-align: left;">%s</pre>', (++$i % 2) ? 'df0' : 'fda', htmlspecialchars($result, ENT_QUOTES));
		}

		echo $result . "\n";
	}
}

function Export($name, $data)
{
	$result = null;

	if (is_scalar($data) === true)
	{
		$result .= sprintf("%s = %s;\n", $name, var_export($data, true));
	}

	else if (is_array($data) === true)
	{
		$result .= sprintf("%s = array();\n", $name);

		foreach ($data as $key => $value)
		{
			$result .= Export($name . '[' . var_export($key, true) . ']', $value) . "\n";
		}

		if (array_keys($data) === range(0, count($data)))
		{
			$result = preg_replace('~^' . sprintf(preg_quote($name . '[%s]', '~'), '\d+') . '~m', $name . '[]', $result);
		}
	}

	else if (is_object($data) === true)
	{
		$result .= sprintf("%s = %s;\n", $name, preg_replace('~\n\s*~', '', var_export($data, true)));
	}

	else
	{
		$result .= sprintf("%s = %s;\n", $name, 'null');
	}

	return rtrim($result, "\n");
}

function Flatten($data)
{
	$result = array();

	if (is_array($data) === true)
	{
		foreach (new RecursiveIteratorIterator(new RecursiveArrayIterator($data)) as $value)
		{
			$result[] = $value;
		}
	}

	return $result;
}

?>