public static function partitionTwo(DataSet $wholeSet, $partitionRelation, $seed = null)
{
if (!is_numeric($partitionRelation) || $partitionRelation <= 0 || $partitionRelation >= 1) {
throw new InvalidArgumentException();
}
// mt_srand(null) === mt_srand(0)
if ($seed !== null) {
mt_srand($seed);
}
$numElements = count($wholeSet->getData());
$indexes = range(0, $numElements - 1);
self::shuffle($indexes);
$trainingSet = [];
$trainingSetLabels = [];
$testSet = [];
$testSetLabels = [];
$data = $wholeSet->getData();
$labels = $wholeSet->getLabels();
for ($i = 0; $i < $numElements; $i++) {
$index = $indexes[$i];
if ($i < $partitionRelation * $numElements) {
$trainingSet[] = $data[$index];
$trainingSetLabels[] = $labels[$index];
} else {
$testSet[] = $data[$index];
$testSetLabels[] = $labels[$index];
}
}
$trainingDataSet = new DataSet($trainingSet, $trainingSetLabels);
$testDataSet = new DataSet($testSet, $testSetLabels);
return new Partition($trainingDataSet, $testDataSet);
}
public function __construct(DataSet $wholeSet, $numberOfPartitions, $seed = null)
{
$this->data = $wholeSet->getData();
$this->dataSize = count($this->data);
$this->partitionSize = $this->dataSize / $numberOfPartitions;
$this->labels = $wholeSet->getLabels();
$this->numberOfPartitions = $numberOfPartitions;
// null seed: random
// false seed: no shuffling
if ($seed !== false) {
if ($seed !== null) {
mt_srand($seed);
}
$this->shuffle();
}
}