[SPARK-6790][ML] Add spark.ml LinearRegression import/export

This replaces [https://github.com/apache/spark/pull/9656] with updates.

fayeshine should be the main author when this PR is committed.

CC: mengxr fayeshine

Author: Wenjian Huang <nextrush@163.com>
Author: Joseph K. Bradley <joseph@databricks.com>

Closes #9814 from jkbradley/fayeshine-patch-6790.

1 files changed, 32 insertions, 2 deletions

diff --git a/mllib/src/test/scala/org/apache/spark/ml/regression/LinearRegressionSuite.scala b/mllib/src/test/scala/org/apache/spark/ml/regression/LinearRegressionSuite.scala
index a1d86fe8fe..2bdc0e184d 100644
--- a/mllib/src/test/scala/org/apache/spark/ml/regression/LinearRegressionSuite.scala
+++ b/mllib/src/test/scala/org/apache/spark/ml/regression/LinearRegressionSuite.scala
@@ -22,14 +22,15 @@ import scala.util.Random
 import org.apache.spark.SparkFunSuite
 import org.apache.spark.ml.feature.Instance
 import org.apache.spark.ml.param.ParamsSuite
-import org.apache.spark.ml.util.MLTestingUtils
+import org.apache.spark.ml.util.{DefaultReadWriteTest, MLTestingUtils}
 import org.apache.spark.mllib.regression.LabeledPoint
 import org.apache.spark.mllib.linalg.{Vector, DenseVector, Vectors}
 import org.apache.spark.mllib.util.{LinearDataGenerator, MLlibTestSparkContext}
 import org.apache.spark.mllib.util.TestingUtils._
 import org.apache.spark.sql.{DataFrame, Row}
 
-class LinearRegressionSuite extends SparkFunSuite with MLlibTestSparkContext {
+class LinearRegressionSuite
+  extends SparkFunSuite with MLlibTestSparkContext with DefaultReadWriteTest {
 
   private val seed: Int = 42
   @transient var datasetWithDenseFeature: DataFrame = _
@@ -854,4 +855,33 @@ class LinearRegressionSuite extends SparkFunSuite with MLlibTestSparkContext {
     model.summary.tValues.zip(tValsR).foreach{ x => assert(x._1 ~== x._2 absTol 1E-3) }
     model.summary.pValues.zip(pValsR).foreach{ x => assert(x._1 ~== x._2 absTol 1E-3) }
   }
+
+  test("read/write") {
+    def checkModelData(model: LinearRegressionModel, model2: LinearRegressionModel): Unit = {
+      assert(model.intercept === model2.intercept)
+      assert(model.coefficients === model2.coefficients)
+    }
+    val lr = new LinearRegression()
+    testEstimatorAndModelReadWrite(lr, datasetWithWeight, LinearRegressionSuite.allParamSettings,
+      checkModelData)
+  }
+}
+
+object LinearRegressionSuite {
+
+  /**
+   * Mapping from all Params to valid settings which differ from the defaults.
+   * This is useful for tests which need to exercise all Params, such as save/load.
+   * This excludes input columns to simplify some tests.
+   */
+  val allParamSettings: Map[String, Any] = Map(
+    "predictionCol" -> "myPrediction",
+    "regParam" -> 0.01,
+    "elasticNetParam" -> 0.1,
+    "maxIter" -> 2,  // intentionally small
+    "fitIntercept" -> true,
+    "tol" -> 0.8,
+    "standardization" -> false,
+    "solver" -> "l-bfgs"
+  )
 }