Github user dbtsai commented on a diff in the pull request:
https://github.com/apache/spark/pull/15628#discussion_r107312194
--- Diff:
mllib-local/src/main/scala/org/apache/spark/ml/linalg/Matrices.scala ---
@@ -587,18 +722,69 @@ class SparseMatrix @Since("2.0.0") (
}
}
+ override def numNonzeros: Int = values.count(_ != 0)
+
+ override def numActives: Int = values.length
+
/**
- * Generate a `DenseMatrix` from the given `SparseMatrix`. The new
matrix will have isTransposed
- * set to false.
+ * Generate a `SparseMatrix` from this `SparseMatrix`, removing explicit
zero values if they
+ * exist.
+ *
+ * @param colMajor Whether or not the resulting `SparseMatrix` values
are in column major
+ * order.
*/
- @Since("2.0.0")
- def toDense: DenseMatrix = {
- new DenseMatrix(numRows, numCols, toArray)
+ private[ml] override def toSparseMatrix(colMajor: Boolean): SparseMatrix
= {
+ if (!(colMajor ^ isTransposed)) {
+ // breeze transpose rearranges values in column major and removes
explicit zeros
+ if (!isTransposed) {
+ // it is row major and we want col major
+ val breezeTransposed = asBreeze.asInstanceOf[BSM[Double]].t
+
Matrices.fromBreeze(breezeTransposed).transpose.asInstanceOf[SparseMatrix]
+ } else {
+ // it is col major and we want row major
+ val breezeTransposed = asBreeze.asInstanceOf[BSM[Double]]
+ Matrices.fromBreeze(breezeTransposed).asInstanceOf[SparseMatrix]
+ }
+ } else {
--- End diff --
Can we document here that it's when the layout of this and colMajor is
different? Easier read than `(colMajor ^ isTranspose)` condition here. Even
more readable to use pattern matching with exact boolean on both variables.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
