fixed MLlib Naive-Bayes java example bug

the filter tests Double objects by references whereas it should test their values

Author: Dariusz Kobylarz <[email protected]>

Closes #3081 from dkobylarz/master and squashes the following commits:

5d43a39 [Dariusz Kobylarz] naive bayes example update
a304b93 [Dariusz Kobylarz] fixed MLlib Naive-Bayes java example bug

Author: dkobylarz

docs/mllib-naive-bayes.md

@@ -88,11 +88,11 @@ JavaPairRDD<Double, Double> predictionAndLabel =
       return new Tuple2<Double, Double>(model.predict(p.features()), p.label());
     }
   });
-double accuracy = 1.0 * predictionAndLabel.filter(new Function<Tuple2<Double, Double>, Boolean>() {
+double accuracy = predictionAndLabel.filter(new Function<Tuple2<Double, Double>, Boolean>() {
     @Override public Boolean call(Tuple2<Double, Double> pl) {
-      return pl._1() == pl._2();
+      return pl._1().equals(pl._2());
     }
-  }).count() / test.count();
+  }).count() / (double) test.count();
 {% endhighlight %}
 </div>