Repository: spark Updated Branches: refs/heads/branch-1.6 2ddd10486 -> bfcc8cfee
[SPARK-11497][MLLIB][PYTHON] PySpark RowMatrix Constructor Has Type Erasure Issue As noted in PR #9441, implementing `tallSkinnyQR` uncovered a bug with our PySpark `RowMatrix` constructor. As discussed on the dev list [here](http://apache-spark-developers-list.1001551.n3.nabble.com/K-Means-And-Class-Tags-td10038.html), there appears to be an issue with type erasure with RDDs coming from Java, and by extension from PySpark. Although we are attempting to construct a `RowMatrix` from an `RDD[Vector]` in [PythonMLlibAPI](https://github.com/apache/spark/blob/master/mllib/src/main/scala/org/apache/spark/mllib/api/python/PythonMLLibAPI.scala#L1115), the `Vector` type is erased, resulting in an `RDD[Object]`. Thus, when calling Scala's `tallSkinnyQR` from PySpark, we get a Java `ClassCastException` in which an `Object` cannot be cast to a Spark `Vector`. As noted in the aforementioned dev list thread, this issue was also encountered with `DecisionTrees`, and the fix involved an explicit `retag` of the RDD with a `Vector` type. `IndexedRowMatrix` and `CoordinateMatri x` do not appear to have this issue likely due to their related helper functions in `PythonMLlibAPI` creating the RDDs explicitly from DataFrames with pattern matching, thus preserving the types. This PR currently contains that retagging fix applied to the `createRowMatrix` helper function in `PythonMLlibAPI`. This PR blocks #9441, so once this is merged, the other can be rebased. cc holdenk Author: Mike Dusenberry <mwdus...@us.ibm.com> Closes #9458 from dusenberrymw/SPARK-11497_PySpark_RowMatrix_Constructor_Has_Type_Erasure_Issue. (cherry picked from commit 1b8220387e6903564f765fabb54be0420c3e99d7) Signed-off-by: Joseph K. Bradley <jos...@databricks.com> Project: http://git-wip-us.apache.org/repos/asf/spark/repo Commit: http://git-wip-us.apache.org/repos/asf/spark/commit/bfcc8cfe Tree: http://git-wip-us.apache.org/repos/asf/spark/tree/bfcc8cfe Diff: http://git-wip-us.apache.org/repos/asf/spark/diff/bfcc8cfe Branch: refs/heads/branch-1.6 Commit: bfcc8cfee7219e63d2f53fc36627f95dc60428eb Parents: 2ddd104 Author: Mike Dusenberry <mwdus...@us.ibm.com> Authored: Fri Dec 11 14:21:33 2015 -0800 Committer: Joseph K. Bradley <jos...@databricks.com> Committed: Fri Dec 11 14:21:48 2015 -0800 ---------------------------------------------------------------------- .../scala/org/apache/spark/mllib/api/python/PythonMLLibAPI.scala | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/spark/blob/bfcc8cfe/mllib/src/main/scala/org/apache/spark/mllib/api/python/PythonMLLibAPI.scala ---------------------------------------------------------------------- diff --git a/mllib/src/main/scala/org/apache/spark/mllib/api/python/PythonMLLibAPI.scala b/mllib/src/main/scala/org/apache/spark/mllib/api/python/PythonMLLibAPI.scala index 2aa6aec..8d546e3 100644 --- a/mllib/src/main/scala/org/apache/spark/mllib/api/python/PythonMLLibAPI.scala +++ b/mllib/src/main/scala/org/apache/spark/mllib/api/python/PythonMLLibAPI.scala @@ -1143,7 +1143,7 @@ private[python] class PythonMLLibAPI extends Serializable { * Wrapper around RowMatrix constructor. */ def createRowMatrix(rows: JavaRDD[Vector], numRows: Long, numCols: Int): RowMatrix = { - new RowMatrix(rows.rdd, numRows, numCols) + new RowMatrix(rows.rdd.retag(classOf[Vector]), numRows, numCols) } /** --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@spark.apache.org For additional commands, e-mail: commits-h...@spark.apache.org
