Don't overwrite log priors

Author: andrewdalpino

src/Classifiers/NaiveBayes.php

@@ -254,7 +254,7 @@ public function partial(Dataset $dataset) : void
                     }
                 }
 
-                $total = array_sum($columnCounts) + (count($columnCounts) * $this->smoothing);
+                $total = array_sum($columnCounts) + $this->smoothing * count($columnCounts);
 
                 $probs = [];
 
@@ -275,8 +275,6 @@ public function partial(Dataset $dataset) : void
         if ($this->fitPriors) {
             $total = array_sum($this->classCounts);
 
-            $this->logPriors = [];
-
             foreach ($this->classCounts as $class => $weight) {
                 $this->logPriors[$class] = log($weight / $total);
             }