[],Type::NEGATIVE => []]; private $documents = [Type::POSITIVE => 0,Type::NEGATIVE => 0]; public function guess($statement) { $words = $this->getWords($statement); // get the words $best_likelihood = 0; $best_type = null; foreach ($this->types as $type) { $likelihood = $this->pTotal($type); // calculate P(Type) foreach ($words as $word) { $likelihood *= $this->p($word,$type); // calculate P(word,Type) } if ($likelihood > $best_likelihood) { $best_likelihood = $likelihood; $best_type = $type; } } return $best_type; } public function learn($statement,$type) { $words = $this->getWords($statement); foreach ($words as $word) { if (!isset($this->words[$type][$word])) { $this->words[$type][$word] = 0; } $this->words[$type][$word]++; // increment the word count for the type } $this->documents[$type]++; // increment the document count for the type } public function p($word,$type) { $count = 0; if (isset($this->words[$type][$word])) { $count = $this->words[$type][$word]; } return ($count + 1) / (array_sum($this->words[$type]) + 1); } public function pTotal($type) { return ($this->documents[$type] + 1) / (array_sum($this->documents) + 1); } public function getWords($string) { return preg_split('/\s+/',strtolower($string))); } } $classifier = new Classifier(); $classifier->learn('Symfony is the best',Type::NEGATIVE); var_dump($classifier->guess('Symfony is great')); // string(8) "positive" var_dump($classifier->guess('I complain a lot')); // string(8) "negative"