/**
* Calculates the Jacard Similarity between the comparators' scalar attributes
* @param Comparator $a
* @param Comparator $b
* @return float Jaccard Similarity
*/
public function analyse(Comparator $a, Comparator $b)
{
$aa = $a->getScalarAttributes();
$ba = $b->getScalarAttributes();
if (count($aa) != count($ba)) {
throw new \LogicException("Cannot compute similary: attributes arrays are unequal");
}
if (count($aa) == 0 && count($ba) == 0) {
return 1;
}
//follows the convention that two empty objects are equal
$this->similarity = count(array_intersect_assoc($aa, $ba)) / count($aa);
return $this->similarity;
}
/**
* Accessor for the attribute filler before it is applied to the Comparators
* This will compute the union set of attributes using the keys and return an array filled with the filler value specified
* @param string $attributeType vector|scalar
* @param mixed $replaceWith The value to fill the missing attributes with
* @return array
*/
public function getNormalizedAttributeFiller($attributeType, $replaceWith)
{
$filler = array_fill_keys(array_keys(array_diff_key($this->a->getAttributes($attributeType), $this->b->getAttributes($attributeType)) + array_diff_key($this->b->getAttributes($attributeType), $this->a->getAttributes($attributeType))), $replaceWith);
ksort($filler);
return $filler;
}
