Test build #38683 has finished for PR 7722 at commit dcd757b.

• This patch fails Scala style tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class RobustRegression(override val uid: String)
  • public static class StructWriter
  • abstract class InternalRow extends Serializable with SpecializedGetters
  • implicit class DslLogicalPlan(val logicalPlan: LogicalPlan)
  • case class CreateStructUnsafe(children: Seq[Expression]) extends Expression
  • case class CreateNamedStructUnsafe(children: Seq[Expression]) extends Expression
  • case class LastDay(startDate: Expression) extends UnaryExpression with ImplicitCastInputTypes
  • case class NextDay(startDate: Expression, dayOfWeek: Expression)
  • case class TungstenProject(projectList: Seq[NamedExpression], child: SparkPlan) extends UnaryNode

Test build #38787 has finished for PR 7722 at commit fbd0b64.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class RobustRegression(override val uid: String)
  • implicit class DslLogicalPlan(val logicalPlan: LogicalPlan)

Test build #38829 has finished for PR 7722 at commit c980a1f.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class RobustRegression(override val uid: String)

Test build #38827 has finished for PR 7722 at commit e693c54.

• This patch fails PySpark unit tests.
• This patch does not merge cleanly.
• This patch adds the following public classes (experimental):
  • class RobustRegression(override val uid: String)

Test build #38826 has finished for PR 7722 at commit dd70763.

• This patch passes all tests.
• This patch does not merge cleanly.
• This patch adds the following public classes (experimental):
  • class RobustRegression(override val uid: String)

Test build #38828 has finished for PR 7722 at commit 952dcab.

• This patch passes all tests.
• This patch does not merge cleanly.
• This patch adds the following public classes (experimental):
  • class RobustRegression(override val uid: String)

@dbtsai @srowen Need your input to decide whether we want to add costFunc: Param[String] to LinearRegression or create a new class RobustRegression (or RobustLinearRegression).

@dbtsai @srowen Need your input to decide whether we want to add costFunc: Param[String] to LinearRegression or create a new class RobustRegression (or RobustLinearRegression).

Hm... I suppose I would expect to optionally change the cost function to something like absolute error, rather than introduce a different class. this is still essentially linear regression right?

If the difference is more than the cost function, I could see making a parallel implementation, but that seems like a lot of duplication to avoid if possible.

Discussed with @dbtsai offline. He suggested using LinearRegression since the output model remains the same no matter what loss function we use.

I will have them in the same LinearRegression codebase as @mengxr said. Almost 90% of the code is the same, and it will be hard to maintain. BTW, I can take over this PR for code-review.

We also need the unit-tests.

Test build #39626 has finished for PR 7722 at commit cff7ecb.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

Please add the unit tests. Thanks.

Test build #39782 has finished for PR 7722 at commit 5a94f99.

• This patch fails to build.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class RobustRegression(override val uid: String)

Test build #39786 has finished for PR 7722 at commit 412c34d.

• This patch fails to build.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class RobustRegression(override val uid: String)

@AmplabJenkins I can build. Can you re-test please?

Test build #39793 has finished for PR 7722 at commit 4f0865f.

• This patch fails to build.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class RobustRegression(override val uid: String)

@AmplabJenkins Need your help. I can build with this command:
sbt publish-local -Pyarn -Phadoop-2.4 -Dhadoop.version=2.5.2

and I can run all the tests.

Please help understand the errors:
not enough arguments for constructor LinearRegressionTrainingSummary: (predictions: org.apache.spark.sql.DataFrame, predictionCol: String, labelCol: String, featuresCol: String, objectiveHistory: Array[Double])org.apache.spark.ml.regression.LinearRegressionTrainingSummary.
[error] Unspecified value parameter objectiveHistory.
[error] val trainingSummary = new LinearRegressionTrainingSummary(

Test build #39949 has finished for PR 7722 at commit a79855a.

• This patch fails Spark unit tests.
• This patch does not merge cleanly.
• This patch adds the following public classes (experimental):
  • class RobustRegression(override val uid: String)