[SPARK-13782][ML] Model export/import for spark.ml: BisectingKMeans

## What changes were proposed in this pull request?
jira: https://issues.apache.org/jira/browse/SPARK-13782
Model export/import for BisectingKMeans in spark.ml and mllib

## How was this patch tested?

unit tests

Author: Yuhao Yang <hhbyyh@gmail.com>

Closes #11933 from hhbyyh/bisectingsave.

2 files changed, 39 insertions, 1 deletions

diff --git a/mllib/src/test/scala/org/apache/spark/ml/clustering/BisectingKMeansSuite.scala b/mllib/src/test/scala/org/apache/spark/ml/clustering/BisectingKMeansSuite.scala
index b719a8c7e7..18f2c994b4 100644
--- a/mllib/src/test/scala/org/apache/spark/ml/clustering/BisectingKMeansSuite.scala
+++ b/mllib/src/test/scala/org/apache/spark/ml/clustering/BisectingKMeansSuite.scala
@@ -18,10 +18,12 @@
 package org.apache.spark.ml.clustering
 
 import org.apache.spark.SparkFunSuite
+import org.apache.spark.ml.util.DefaultReadWriteTest
 import org.apache.spark.mllib.util.MLlibTestSparkContext
 import org.apache.spark.sql.DataFrame
 
-class BisectingKMeansSuite extends SparkFunSuite with MLlibTestSparkContext {
+class BisectingKMeansSuite
+  extends SparkFunSuite with MLlibTestSparkContext with DefaultReadWriteTest {
 
   final val k = 5
   @transient var dataset: DataFrame = _
@@ -84,4 +86,22 @@ class BisectingKMeansSuite extends SparkFunSuite with MLlibTestSparkContext {
     assert(model.computeCost(dataset) < 0.1)
     assert(model.hasParent)
   }
+
+  test("read/write") {
+    def checkModelData(model: BisectingKMeansModel, model2: BisectingKMeansModel): Unit = {
+      assert(model.clusterCenters === model2.clusterCenters)
+    }
+    val bisectingKMeans = new BisectingKMeans()
+    testEstimatorAndModelReadWrite(
+      bisectingKMeans, dataset, BisectingKMeansSuite.allParamSettings, checkModelData)
+  }
+}
+
+object BisectingKMeansSuite {
+  val allParamSettings: Map[String, Any] = Map(
+    "k" -> 3,
+    "maxIter" -> 2,
+    "seed" -> -1L,
+    "minDivisibleClusterSize" -> 2.0
+  )
 }
diff --git a/mllib/src/test/scala/org/apache/spark/mllib/clustering/BisectingKMeansSuite.scala b/mllib/src/test/scala/org/apache/spark/mllib/clustering/BisectingKMeansSuite.scala
index 41b9d5c0d9..35f7932ae8 100644
--- a/mllib/src/test/scala/org/apache/spark/mllib/clustering/BisectingKMeansSuite.scala
+++ b/mllib/src/test/scala/org/apache/spark/mllib/clustering/BisectingKMeansSuite.scala
@@ -21,6 +21,7 @@ import org.apache.spark.SparkFunSuite
 import org.apache.spark.mllib.linalg.Vectors
 import org.apache.spark.mllib.util.MLlibTestSparkContext
 import org.apache.spark.mllib.util.TestingUtils._
+import org.apache.spark.util.Utils
 
 class BisectingKMeansSuite extends SparkFunSuite with MLlibTestSparkContext {
 
@@ -179,4 +180,21 @@ class BisectingKMeansSuite extends SparkFunSuite with MLlibTestSparkContext {
       }
     }
   }
+
+  test("BisectingKMeans model save/load") {
+    val tempDir = Utils.createTempDir()
+    val path = tempDir.toURI.toString
+
+    val points = (1 until 8).map(i => Vectors.dense(i))
+    val data = sc.parallelize(points, 2)
+    val model = new BisectingKMeans().run(data)
+    try {
+      model.save(sc, path)
+      val sameModel = BisectingKMeansModel.load(sc, path)
+      assert(model.k === sameModel.k)
+      model.clusterCenters.zip(sameModel.clusterCenters).foreach(c => c._1 === c._2)
+    } finally {
+      Utils.deleteRecursively(tempDir)
+    }
+  }
 }