function updateCentroids($mapping, $data, $k)
{
$centroids = array();
$counts = array_count_values($mapping);
foreach ($mapping as $documentID => $centroidID) {
foreach ($data[$documentID] as $dim => $value) {
if (!isset($cenntroids[$centroidID][$dim])) {
$centroids[$centroidID][$dim] = 0;
}
$centroids[$centroidID][$dim] += $value / $counts[$centroidID];
}
}
if (count($centroids) < $k) {
$centroids = array_merge($centroids, initialiseCentroids($data, $k - count($centroids)));
}
return $centroids;
}
function updateCentroids($mapDocToCentroid, $normalisedTfidf, $numClusters)
{
$centroids = array();
$counts = array_count_values($mapDocToCentroid);
// for each doc in the mapping
foreach ($mapDocToCentroid as $docID => $centroidID) {
// For the corresponding doc in the data array, loop over each term
foreach ($normalisedTfidf[$docID] as $term => $tfidfValue) {
// Update the centroid by calculating average of all tfidf in each centroid
if (isset($centroids[$centroidID][$term])) {
$centroids[$centroidID][$term] += $tfidfValue / $counts[$centroidID];
}
}
}
// Continue to generate new centroids until the set number of clusters is reached
if (count($centroids) < $numClusters) {
$centroids = array_merge($centroids, initialiseCentroids($normalisedTfidf, $numClusters - count($centroids)));
}
return $centroids;
}
