address comment and add mima excludes

Author: mengxr

mllib/src/main/scala/org/apache/spark/mllib/linalg/Vectors.scala

@@ -118,7 +118,8 @@ sealed trait Vector extends Serializable {
   private[spark] def foreachActive(f: (Int, Double) => Unit)
 
   /**
-   * Number of active entries. Inactive entries are all zeros, while active entries could be zero.
+   * Number of active entries.  An "active entry" is an element which is explicitly stored,
+   * regardless of its value.  Note that inactive entries have value 0.
    */
   def numActives: Int
 

project/MimaExcludes.scala

@@ -76,6 +76,18 @@ object MimaExcludes {
             // SPARK-7090 Introduce LDAOptimizer to LDA to further improve extensibility
             ProblemFilters.exclude[MissingClassProblem](
               "org.apache.spark.mllib.clustering.LDA$EMOptimizer")
+          ) ++ Seq(
+            // SPARK-6756 add toSparse, toDense, numActives, numNonzeros, and compressed to Vector
+            ProblemFilters.exclude[MissingMethodProblem](
+              "org.apache.spark.mllib.linalg.Vector.compressed"),
+            ProblemFilters.exclude[MissingMethodProblem](
+              "org.apache.spark.mllib.linalg.Vector.toDense"),
+            ProblemFilters.exclude[MissingMethodProblem](
+              "org.apache.spark.mllib.linalg.Vector.numNonzeros"),
+            ProblemFilters.exclude[MissingMethodProblem](
+              "org.apache.spark.mllib.linalg.Vector.toSparse"),
+            ProblemFilters.exclude[MissingMethodProblem](
+              "org.apache.spark.mllib.linalg.Vector.numActives")
           )
 
         case v if v.startsWith("1.3") =>