Github user srowen commented on a diff in the pull request:
https://github.com/apache/spark/pull/18624#discussion_r127200571
--- Diff:
mllib/src/main/scala/org/apache/spark/mllib/recommendation/MatrixFactorizationModel.scala
---
@@ -286,40 +288,124 @@ object MatrixFactorizationModel extends
Loader[MatrixFactorizationModel] {
srcFeatures: RDD[(Int, Array[Double])],
dstFeatures: RDD[(Int, Array[Double])],
num: Int): RDD[(Int, Array[(Int, Double)])] = {
- val srcBlocks = blockify(srcFeatures)
- val dstBlocks = blockify(dstFeatures)
- val ratings = srcBlocks.cartesian(dstBlocks).flatMap { case (srcIter,
dstIter) =>
- val m = srcIter.size
- val n = math.min(dstIter.size, num)
- val output = new Array[(Int, (Int, Double))](m * n)
- var i = 0
- val pq = new BoundedPriorityQueue[(Int,
Double)](n)(Ordering.by(_._2))
- srcIter.foreach { case (srcId, srcFactor) =>
- dstIter.foreach { case (dstId, dstFactor) =>
- // We use F2jBLAS which is faster than a call to native BLAS for
vector dot product
- val score = BLAS.f2jBLAS.ddot(rank, srcFactor, 1, dstFactor, 1)
- pq += dstId -> score
- }
- pq.foreach { case (dstId, score) =>
- output(i) = (srcId, (dstId, score))
+ val srcBlocks = blockify(rank, srcFeatures).zipWithIndex()
+ val dstBlocks = blockify(rank, dstFeatures)
+ val ratings = srcBlocks.cartesian(dstBlocks).map {
+ case (((srcIds, srcFactors), index), (dstIds, dstFactors)) =>
+ val m = srcIds.length
+ val n = dstIds.length
+ val dstIdMatrix = new Array[Int](m * num)
+ val scoreMatrix = Array.fill[Double](m * num)(Double.MinValue)
+ val pq = new BoundedPriorityQueue[(Int,
Double)](num)(Ordering.by(_._2))
+
+ val ratings = srcFactors.transpose.multiply(dstFactors)
+ var i = 0
+ var j = 0
+ while (i < m) {
+ var k = 0
+ while (k < n) {
+ pq += dstIds(k) -> ratings(i, k)
+ k += 1
+ }
+ var size = pq.size
+ while(size > 0) {
+ size -= 1
+ val factor = pq.poll
--- End diff --
poll() because it has side effects
---
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 infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org
For additional commands, e-mail: reviews-h...@spark.apache.org
