/**
* Constructor function
*
* @param array $observations An array of 1 x n matrices, where n is how many dimensions the data has
* @param int $k The number of clusters to use
*/
public function __construct(array $observations, $k, GeneratorInterface $gen, MatrixBuilder $mBuilder, MatrixMath $mMath)
{
$this->generator = $gen;
$this->mbuilder = $mBuilder;
$this->mmath = $mMath;
for ($i = 0; $i < $k; $i++) {
$this->centroids[] = $observations[0];
//Fill centroids with vectors. The specific values will be overwritten before use.
}
foreach ($observations as $observation) {
$obs_array = array();
$obs_array['coordinates'] = $observation;
$obs_array['centroid'] = $this->generator->generate(0, $k - 1);
//Randomly assign observations to centroids, according to the Random Partition method.
$this->observations[] = $obs_array;
}
//Iterate until convergence is reached. i.e. when cluster assignments no longer change
$change = true;
while ($change) {
$this->update();
$change = $this->assign();
}
}
/**
* Fetch a random float value
*
* @access protected
* @return float the random value between 0 and 1
*/
protected function randFloat()
{
return $this->generator->generate(0, $this->generator->max()) / $this->generator->max();
//A number between 0 and 1.
}
/**
* Return the smallest possible random value
*
* @access public
* @return double
*/
public function min($value = null)
{
return $this->internal->min($value);
}
/**
* Calculate a random numer of repeats given the current min-max range
*
* @access public
* @param GeneratorInterface $generator
* @return Integer
*/
public function calculateRepeatQuota(GeneratorInterface $generator)
{
$repeat_x = $this->getMinOccurances();
if ($this->getOccuranceRange() > 0) {
$repeat_x = (int) \round($generator->generate($this->getMinOccurances(), $this->getMaxOccurances()));
}
return $repeat_x;
}
/**
* This function is like rand
*
* @param array $weights
* @param GeneratorInterface $random
* @return float
*/
public function getWeightedRand($weights, GeneratorInterface $random)
{
$r = $random->generate(1, 1000);
$offset = 0;
foreach ($weights as $k => $w) {
$offset += $w * 1000;
if ($r <= $offset) {
return $k;
}
}
}