Updated the score function

Author: chewxy

tfidf.go

@@ -67,17 +67,13 @@ func (tf *TFIDF) Score(doc Document) []float64 {
 	ids := doc.IDs()
 
 	retVal := make([]float64, len(ids))
-	tf.Lock()
+	TF := make(map[int]float64)
 	for _, id := range ids {
-		tf.TF[id]++
+		TF[id]++
 	}
 	for i, id := range ids {
-		retVal[i] = tf.TF[id]
-	}
-	for _, id := range ids {
-		tf.TF[id]--
+		retVal[i] = TF[id]
 	}
-	tf.Unlock()
 
 	l := float64(len(ids))
 	for i, freq := range retVal {

tfidf_example_test.go

@@ -89,5 +89,5 @@ func Example() {
 	// 	"never": 2.4
 	// 	"mind": 2.4
 	// 	"how": 2.4
-	// Scores: [1.2 1.3 1.2 0.9]
+	// Scores: [0.6 0.3 0.6 0.1]
 }