You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@mahout.apache.org by ra...@apache.org on 2018/06/27 14:51:49 UTC

[21/51] [partial] mahout git commit: MAHOUT-2042 and MAHOUT-2045 Delete directories which were moved/no longer in use

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/cf/SimilarityAnalysis.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/cf/SimilarityAnalysis.scala b/math-scala/src/main/scala/org/apache/mahout/math/cf/SimilarityAnalysis.scala
deleted file mode 100644
index f69bf81..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/cf/SimilarityAnalysis.scala
+++ /dev/null
@@ -1,453 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math.cf
-
-import org.apache.mahout.math._
-import org.apache.mahout.math.indexeddataset.IndexedDataset
-import scalabindings._
-import RLikeOps._
-import drm._
-import RLikeDrmOps._
-import scala.collection.JavaConversions._
-import org.apache.mahout.math.stats.LogLikelihood
-import collection._
-import org.apache.mahout.math.function.{VectorFunction, Functions}
-
-import scala.util.Random
-
-
-/**
- * Based on "Ted Dunnning & Ellen Friedman: Practical Machine Learning, Innovations in Recommendation",
- * available at http://www.mapr.com/practical-machine-learning
- *
- * see also "Sebastian Schelter, Christoph Boden, Volker Markl:
- * Scalable Similarity-Based Neighborhood Methods with MapReduce
- * ACM Conference on Recommender Systems 2012"
- */
-object SimilarityAnalysis extends Serializable {
-
-  /** Compares (Int,Double) pairs by the second value */
-  private val orderByScore = Ordering.fromLessThan[(Int, Double)] { case ((_, score1), (_, score2)) => score1 > score2}
-
-  lazy val defaultParOpts = ParOpts()
-
-  /**
-   * Calculates item (column-wise) similarity using the log-likelihood ratio on A'A, A'B, A'C, ...
-   * and returns a list of similarity and cross-similarity matrices
-    *
-    * @param drmARaw Primary interaction matrix
-   * @param randomSeed when kept to a constant will make repeatable downsampling
-   * @param maxInterestingItemsPerThing number of similar items to return per item, default: 50
-   * @param maxNumInteractions max number of interactions after downsampling, default: 500
-   * @param parOpts partitioning params for drm.par(...)
-   * @return a list of [[org.apache.mahout.math.drm.DrmLike]] containing downsampled DRMs for cooccurrence and
-   *         cross-cooccurrence
-   */
-  def cooccurrences(
-    drmARaw: DrmLike[Int],
-    randomSeed: Int = 0xdeadbeef,
-    maxInterestingItemsPerThing: Int = 50,
-    maxNumInteractions: Int = 500,
-    drmBs: Array[DrmLike[Int]] = Array(),
-    parOpts: ParOpts = defaultParOpts)
-    : List[DrmLike[Int]] = {
-
-    implicit val distributedContext = drmARaw.context
-
-    // backend partitioning defaults to 'auto', which is often better decided by calling funciton
-    // todo:  this should ideally be different per drm
-    drmARaw.par( min = parOpts.minPar, exact = parOpts.exactPar, auto = parOpts.autoPar)
-
-    // Apply selective downsampling, pin resulting matrix
-    val drmA = sampleDownAndBinarize(drmARaw, randomSeed, maxNumInteractions)
-
-    // num users, which equals the maximum number of interactions per item
-    val numUsers = drmA.nrow.toInt
-
-    // Compute & broadcast the number of interactions per thing in A
-    val bcastInteractionsPerItemA = drmBroadcast(drmA.numNonZeroElementsPerColumn)
-
-    // Compute cooccurrence matrix A'A
-    val drmAtA = drmA.t %*% drmA
-
-    // Compute loglikelihood scores and sparsify the resulting matrix to get the similarity matrix
-    val drmSimilarityAtA = computeSimilarities(drmAtA, numUsers, maxInterestingItemsPerThing,
-      bcastInteractionsPerItemA, bcastInteractionsPerItemA, crossCooccurrence = false)
-
-    var similarityMatrices = List(drmSimilarityAtA)
-
-    // Now look at cross cooccurrences
-    for (drmBRaw <- drmBs) {
-      // backend partitioning defaults to 'auto', which is often better decided by calling funciton
-      // todo:  this should ideally be different per drm
-      drmARaw.par( min = parOpts.minPar, exact = parOpts.exactPar, auto = parOpts.autoPar)
-
-      // Down-sample and pin other interaction matrix
-      val drmB = sampleDownAndBinarize(drmBRaw, randomSeed, maxNumInteractions).checkpoint()
-
-      // Compute & broadcast the number of interactions per thing in B
-      val bcastInteractionsPerThingB = drmBroadcast(drmB.numNonZeroElementsPerColumn)
-
-      // Compute cross-cooccurrence matrix A'B
-      val drmAtB = drmA.t %*% drmB
-
-      val drmSimilarityAtB = computeSimilarities(drmAtB, numUsers, maxInterestingItemsPerThing,
-        bcastInteractionsPerItemA, bcastInteractionsPerThingB)
-
-      similarityMatrices = similarityMatrices :+ drmSimilarityAtB
-
-      drmB.uncache()
-    }
-
-    // Unpin downsampled interaction matrix
-    drmA.uncache()
-
-    // Return list of similarity matrices
-    similarityMatrices
-  }
-
-  /**
-   * Calculates item (column-wise) similarity using the log-likelihood ratio on A'A, A'B, A'C, ... and returns
-   * a list of similarity and cross-similarity matrices. Somewhat easier to use method, which handles the ID
-   * dictionaries correctly
-   *
-   * @param indexedDatasets first in array is primary/A matrix all others are treated as secondary
-   * @param randomSeed use default to make repeatable, otherwise pass in system time or some randomizing seed
-   * @param maxInterestingItemsPerThing max similarities per items
-   * @param maxNumInteractions max number of input items per item
-   * @param parOpts partitioning params for drm.par(...)
-   * @return a list of [[org.apache.mahout.math.indexeddataset.IndexedDataset]] containing downsampled
-   *         IndexedDatasets for cooccurrence and cross-cooccurrence
-   */
-  def cooccurrencesIDSs(
-    indexedDatasets: Array[IndexedDataset],
-    randomSeed: Int = 0xdeadbeef,
-    maxInterestingItemsPerThing: Int = 50,
-    maxNumInteractions: Int = 500,
-    parOpts: ParOpts = defaultParOpts):
-    List[IndexedDataset] = {
-    val drms = indexedDatasets.map(_.matrix.asInstanceOf[DrmLike[Int]])
-    val primaryDrm = drms(0)
-    val secondaryDrms = drms.drop(1)
-    val coocMatrices = cooccurrences(primaryDrm, randomSeed, maxInterestingItemsPerThing,
-      maxNumInteractions, secondaryDrms, parOpts)
-    val retIDSs = coocMatrices.iterator.zipWithIndex.map {
-      case( drm, i ) =>
-        indexedDatasets(0).create(drm, indexedDatasets(0).columnIDs, indexedDatasets(i).columnIDs)
-    }
-    retIDSs.toList
-  }
-
-  /**
-    * Calculates item (column-wise) similarity using the log-likelihood ratio on A'A, A'B, A'C, ... and returns
-    * a list of similarity and cross-occurrence matrices. Somewhat easier to use method, which handles the ID
-    * dictionaries correctly and contains info about downsampling in each model calc.
-    *
-    * @param datasets first in array is primary/A matrix all others are treated as secondary, includes information
-    *                 used to downsample the input drm as well as the output llr(A'A), llr(A'B). The information
-    *                 is contained in each dataset in the array and applies to the model calculation of A' with
-    *                 the dataset. Todo: ignoring absolute threshold for now.
-    * @param randomSeed use default to make repeatable, otherwise pass in system time or some randomizing seed
-    * @param parOpts partitioning params for drm.par(...)
-    * @return a list of [[org.apache.mahout.math.indexeddataset.IndexedDataset]] containing downsampled
-    *         IndexedDatasets for cooccurrence and cross-cooccurrence
-    */
-  def crossOccurrenceDownsampled(
-    datasets: List[DownsamplableCrossOccurrenceDataset],
-    randomSeed: Int = 0xdeadbeef):
-    List[IndexedDataset] = {
-
-
-    val crossDatasets = datasets.drop(1) // drop A
-    val primaryDataset = datasets.head // use A throughout
-    val drmARaw = primaryDataset.iD.matrix
-
-    implicit val distributedContext = primaryDataset.iD.matrix.context
-
-    // backend partitioning defaults to 'auto', which is often better decided by calling funciton
-    val parOptsA = primaryDataset.parOpts.getOrElse(defaultParOpts)
-    drmARaw.par( min = parOptsA.minPar, exact = parOptsA.exactPar, auto = parOptsA.autoPar)
-
-    // Apply selective downsampling, pin resulting matrix
-    val drmA = sampleDownAndBinarize(drmARaw, randomSeed, primaryDataset.maxElementsPerRow)
-
-    // num users, which equals the maximum number of interactions per item
-    val numUsers = drmA.nrow.toInt
-
-    // Compute & broadcast the number of interactions per thing in A
-    val bcastInteractionsPerItemA = drmBroadcast(drmA.numNonZeroElementsPerColumn)
-
-    // Compute cooccurrence matrix A'A
-    val drmAtA = drmA.t %*% drmA
-
-    // Compute loglikelihood scores and sparsify the resulting matrix to get the similarity matrix
-    val drmSimilarityAtA = computeSimilarities(drmAtA, numUsers, primaryDataset.maxInterestingElements,
-      bcastInteractionsPerItemA, bcastInteractionsPerItemA, crossCooccurrence = false,
-      minLLROpt = primaryDataset.minLLROpt)
-
-    var similarityMatrices = List(drmSimilarityAtA)
-
-    // Now look at cross cooccurrences
-    for (dataset <- crossDatasets) {
-      // backend partitioning defaults to 'auto', which is often better decided by calling funciton
-      val parOptsB = dataset.parOpts.getOrElse(defaultParOpts)
-      dataset.iD.matrix.par(min = parOptsB.minPar, exact = parOptsB.exactPar, auto = parOptsB.autoPar)
-
-      // Downsample and pin other interaction matrix
-      val drmB = sampleDownAndBinarize(dataset.iD.matrix, randomSeed, dataset.maxElementsPerRow).checkpoint()
-
-      // Compute & broadcast the number of interactions per thing in B
-      val bcastInteractionsPerThingB = drmBroadcast(drmB.numNonZeroElementsPerColumn)
-
-      // Compute cross-cooccurrence matrix A'B
-      val drmAtB = drmA.t %*% drmB
-
-      val drmSimilarityAtB = computeSimilarities(drmAtB, numUsers, dataset.maxInterestingElements,
-        bcastInteractionsPerItemA, bcastInteractionsPerThingB, minLLROpt = dataset.minLLROpt)
-
-      similarityMatrices = similarityMatrices :+ drmSimilarityAtB
-
-      drmB.uncache()
-    }
-
-    // Unpin downsampled interaction matrix
-    drmA.uncache()
-
-    // Return list of datasets
-    val retIDSs = similarityMatrices.iterator.zipWithIndex.map {
-      case( drm, i ) =>
-        datasets(0).iD.create(drm, datasets(0).iD.columnIDs, datasets(i).iD.columnIDs)
-    }
-    retIDSs.toList
-
-  }
-
-  /**
-   * Calculates row-wise similarity using the log-likelihood ratio on AA' and returns a DRM of rows and similar rows
-   *
-   * @param drmARaw Primary interaction matrix
-   * @param randomSeed when kept to a constant will make repeatable downsampling
-   * @param maxInterestingSimilaritiesPerRow number of similar items to return per item, default: 50
-   * @param maxNumInteractions max number of interactions after downsampling, default: 500
-   * @param parOpts partitioning options used for drm.par(...)
-   */
-  def rowSimilarity(
-    drmARaw: DrmLike[Int],
-    randomSeed: Int = 0xdeadbeef,
-    maxInterestingSimilaritiesPerRow: Int = 50,
-    maxNumInteractions: Int = 500,
-    parOpts: ParOpts = defaultParOpts): DrmLike[Int] = {
-
-    implicit val distributedContext = drmARaw.context
-
-    // backend partitioning defaults to 'auto', which is often better decided by calling funciton
-    // todo: should this ideally be different per drm?
-    drmARaw.par(min = parOpts.minPar, exact = parOpts.exactPar, auto = parOpts.autoPar)
-
-    // Apply selective downsampling, pin resulting matrix
-    val drmA = sampleDownAndBinarize(drmARaw, randomSeed, maxNumInteractions)
-
-    // num columns, which equals the maximum number of interactions per item
-    val numCols = drmA.ncol
-
-    // Compute & broadcast the number of interactions per row in A
-    val bcastInteractionsPerItemA = drmBroadcast(drmA.numNonZeroElementsPerRow)
-
-    // Compute row similarity cooccurrence matrix AA'
-    val drmAAt = drmA %*% drmA.t
-
-    // Compute loglikelihood scores and sparsify the resulting matrix to get the similarity matrix
-    val drmSimilaritiesAAt = computeSimilarities(drmAAt, numCols, maxInterestingSimilaritiesPerRow,
-      bcastInteractionsPerItemA, bcastInteractionsPerItemA, crossCooccurrence = false)
-
-    drmSimilaritiesAAt
-  }
-
-  /**
-   * Calculates row-wise similarity using the log-likelihood ratio on AA' and returns a drm of rows and similar rows.
-   * Uses IndexedDatasets, which handle external ID dictionaries properly
-   *
-   * @param indexedDataset compare each row to every other
-   * @param randomSeed  use default to make repeatable, otherwise pass in system time or some randomizing seed
-   * @param maxInterestingSimilaritiesPerRow max elements returned in each row
-   * @param maxObservationsPerRow max number of input elements to use
-   */
-  def rowSimilarityIDS(indexedDataset: IndexedDataset, randomSeed: Int = 0xdeadbeef,
-      maxInterestingSimilaritiesPerRow: Int = 50,
-      maxObservationsPerRow: Int = 500):
-    IndexedDataset = {
-    val coocMatrix = rowSimilarity(indexedDataset.matrix, randomSeed, maxInterestingSimilaritiesPerRow,
-      maxObservationsPerRow)
-    indexedDataset.create(coocMatrix, indexedDataset.rowIDs, indexedDataset.rowIDs)
-  }
-
-   /** Compute loglikelihood ratio see http://tdunning.blogspot.de/2008/03/surprise-and-coincidence.html for details */
-  def logLikelihoodRatio(numInteractionsWithA: Long, numInteractionsWithB: Long,
-    numInteractionsWithAandB: Long, numInteractions: Long) = {
-
-    val k11 = numInteractionsWithAandB
-    val k12 = numInteractionsWithA - numInteractionsWithAandB
-    val k21 = numInteractionsWithB - numInteractionsWithAandB
-    val k22 = numInteractions - numInteractionsWithA - numInteractionsWithB + numInteractionsWithAandB
-
-    LogLikelihood.logLikelihoodRatio(k11, k12, k21, k22)
-
-  }
-
-  def computeSimilarities(
-    drm: DrmLike[Int],
-    numUsers: Int,
-    maxInterestingItemsPerThing: Int,
-    bcastNumInteractionsB: BCast[Vector],
-    bcastNumInteractionsA: BCast[Vector],
-    crossCooccurrence: Boolean = true,
-    minLLROpt: Option[Double] = None) = {
-
-    //val minLLR = minLLROpt.getOrElse(0.0d) // accept all values if not specified
-
-    val minLLR = minLLROpt
-
-    drm.mapBlock() {
-      case (keys, block) =>
-
-        val llrBlock = block.like()
-        val numInteractionsB: Vector = bcastNumInteractionsB
-        val numInteractionsA: Vector = bcastNumInteractionsA
-
-        for (index <- 0 until keys.size) {
-
-          val thingB = keys(index)
-
-          // PriorityQueue to select the top-k items
-          val topItemsPerThing = new mutable.PriorityQueue[(Int, Double)]()(orderByScore)
-
-          block(index, ::).nonZeroes().foreach { elem =>
-            val thingA = elem.index
-            val cooccurrences = elem.get
-
-            // exclude co-occurrences of the item with itself
-            if (crossCooccurrence || thingB != thingA) {
-              // Compute loglikelihood ratio
-              val llr = logLikelihoodRatio(numInteractionsB(thingB).toLong, numInteractionsA(thingA).toLong,
-                cooccurrences.toLong, numUsers)
-
-              val candidate = thingA -> llr
-
-              // legacy hadoop code maps values to range (0..1) via
-              // val normailizedLLR = 1.0 - (1.0 / (1.0 + llr))
-              // val candidate = thingA -> normailizedLLR
-
-              // Enqueue item with score, if belonging to the top-k
-              if(minLLR.isEmpty || llr >= minLLR.get) { // llr threshold takes precedence over max per row
-                if (topItemsPerThing.size < maxInterestingItemsPerThing) {
-                  topItemsPerThing.enqueue(candidate)
-                } else if (orderByScore.lt(candidate, topItemsPerThing.head)) {
-                  topItemsPerThing.dequeue()
-                  topItemsPerThing.enqueue(candidate)
-                }
-              }
-            }
-          }
-
-          // Add top-k interesting items to the output matrix
-          topItemsPerThing.dequeueAll.foreach {
-            case (otherThing, llrScore) =>
-              llrBlock(index, otherThing) = llrScore
-          }
-        }
-
-        keys -> llrBlock
-    }
-  }
-
-  /**
-   * Selectively downsample rows and items with an anomalous amount of interactions, inspired by
-   * https://github.com/tdunning/in-memory-cooccurrence/blob/master/src/main/java/com/tdunning/cooc/Analyze.java
-   *
-   * additionally binarizes input matrix, as we're only interesting in knowing whether interactions happened or not
-   *
-   * @param drmM matrix to downsample
-   * @param seed random number generator seed, keep to a constant if repeatability is neccessary
-   * @param maxNumInteractions number of elements in a row of the returned matrix
-   * @return the downsampled DRM
-   */
-  def sampleDownAndBinarize(drmM: DrmLike[Int], seed: Int, maxNumInteractions: Int) = {
-
-    implicit val distributedContext = drmM.context
-
-    // Pin raw interaction matrix
-    val drmI = drmM.checkpoint()
-
-    // Broadcast vector containing the number of interactions with each thing
-    val bcastNumInteractions = drmBroadcast(drmI.numNonZeroElementsPerColumn)
-
-    val downSampledDrmI = drmI.mapBlock() {
-      case (keys, block) =>
-        val numInteractions: Vector = bcastNumInteractions
-
-        // Use a hash of the unique first key to seed the RNG, makes this computation repeatable in case of
-        //failures
-        val random = new Random(MurmurHash.hash(keys(0), seed))
-
-        val downsampledBlock = block.like()
-
-        // Downsample the interaction vector of each row
-        for (rowIndex <- 0 until keys.size) {
-
-          val interactionsInRow = block(rowIndex, ::)
-
-          val numInteractionsPerRow = interactionsInRow.getNumNonZeroElements()
-
-          val perRowSampleRate = math.min(maxNumInteractions, numInteractionsPerRow) / numInteractionsPerRow
-
-          interactionsInRow.nonZeroes().foreach { elem =>
-            val numInteractionsWithThing = numInteractions(elem.index)
-            val perThingSampleRate = math.min(maxNumInteractions, numInteractionsWithThing) / numInteractionsWithThing
-
-            if (random.nextDouble() <= math.min(perRowSampleRate, perThingSampleRate)) {
-              // We ignore the original interaction value and create a binary 0-1 matrix
-              // as we only consider whether interactions happened or did not happen
-              downsampledBlock(rowIndex, elem.index) = 1
-            }
-          }
-        }
-
-        keys -> downsampledBlock
-    }
-
-    // Unpin raw interaction matrix
-    drmI.uncache()
-
-    downSampledDrmI
-  }
-}
-
-case class ParOpts( // this will contain the default `par` params except for auto = true
-  minPar: Int = -1,
-  exactPar: Int = -1,
-  autoPar: Boolean = true)
-
-/* Used to pass in data and params for downsampling the input data as well as output A'A, A'B, etc. */
-case class DownsamplableCrossOccurrenceDataset(
-  iD: IndexedDataset,
-  maxElementsPerRow: Int = 500, // usually items per user in the input dataset, used to ramdomly downsample
-  maxInterestingElements: Int = 50, // number of items/columns to keep in the A'A, A'B etc. where iD == A, B, C ...
-  minLLROpt: Option[Double] = None, // absolute threshold, takes precedence over maxInterestingElements if present
-  parOpts: Option[ParOpts] = None) // these can be set per dataset and are applied to each of the drms
-                                // in crossOccurrenceDownsampled
-

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/decompositions/ALS.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/decompositions/ALS.scala b/math-scala/src/main/scala/org/apache/mahout/math/decompositions/ALS.scala
deleted file mode 100644
index 8ced112..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/decompositions/ALS.scala
+++ /dev/null
@@ -1,141 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math.decompositions
-
-import org.apache.mahout.math._
-import drm._
-import scalabindings._
-import RLikeDrmOps._
-import RLikeOps._
-import org.apache.log4j.Logger
-import math._
-import org.apache.mahout.common.RandomUtils
-
-/** Simple ALS factorization algotithm. To solve, use train() method. */
-private[math] object ALS {
-
-  private val log = Logger.getLogger(ALS.getClass)
-
-  /**
-   * ALS training result. <P>
-   *
-   * <code>drmU %*% drmV.t</code> is supposed to approximate the input.
-   *
-   * @param drmU U matrix
-   * @param drmV V matrix
-   * @param iterationsRMSE RMSE values afeter each of iteration performed
-   */
-  class Result[K](val drmU: DrmLike[K], val drmV: DrmLike[Int], val iterationsRMSE: Iterable[Double]) {
-    def toTuple = (drmU, drmV, iterationsRMSE)
-  }
-
-  /** Result class for in-core results */
-  class InCoreResult(val inCoreU: Matrix, inCoreV: Matrix, val iterationsRMSE: Iterable[Double]) {
-    def toTuple = (inCoreU, inCoreV, iterationsRMSE)
-  }
-
-  /**
-   * Run Distributed ALS.
-   * <P>
-   *
-   * Example:
-   *
-   * <pre>
-   * val (u,v,errors) = als(input, k).toTuple
-   * </pre>
-   *
-   * ALS runs until (rmse[i-1]-rmse[i])/rmse[i-1] < convergenceThreshold, or i==maxIterations,
-   * whichever earlier.
-   * <P>
-   *
-   * @param drmA The input matrix
-   * @param k required rank of decomposition (number of cols in U and V results)
-   * @param convergenceThreshold stop sooner if (rmse[i-1] - rmse[i])/rmse[i - 1] is less than this
-   *                             value. If <=0 then we won't compute RMSE and use convergence test.
-   * @param lambda regularization rate
-   * @param maxIterations maximum iterations to run regardless of convergence
-   * @tparam K row key type of the input (100 is probably more than enough)
-   * @return { @link org.apache.mahout.math.drm.decompositions.ALS.Result}
-   */
-  def dals[K](
-      drmA: DrmLike[K],
-      k: Int = 50,
-      lambda: Double = 0.0,
-      maxIterations: Int = 10,
-      convergenceThreshold: Double = 0.10
-      ): Result[K] = {
-
-    assert(convergenceThreshold < 1.0, "convergenceThreshold")
-    assert(maxIterations >= 1, "maxIterations")
-
-    // Some mapblock() usage may require to know ClassTag[K] bound
-    implicit val ktag = drmA.keyClassTag
-
-    val drmAt = drmA.t
-
-    // Initialize U and V so that they are identically distributed to A or A'
-    var drmU = drmA.mapBlock(ncol = k) {
-      case (keys, block) =>
-        val rnd = RandomUtils.getRandom()
-        val uBlock = Matrices.symmetricUniformView(block.nrow, k, rnd.nextInt()) * 0.01
-        keys -> uBlock
-    }
-
-    var drmV: DrmLike[Int] = null
-    var rmseIterations: List[Double] = Nil
-
-    // ALS iterator
-    var stop = false
-    var i = 0
-    while (!stop && i < maxIterations) {
-
-      // Alternate. This is really what ALS is.
-      if (drmV != null) drmV.uncache()
-      drmV = (drmAt %*% drmU %*% solve(drmU.t %*% drmU -: diag(lambda, k))).checkpoint()
-
-      drmU.uncache()
-      drmU = (drmA %*% drmV %*% solve(drmV.t %*% drmV -: diag(lambda, k))).checkpoint()
-
-      // Check if we are requested to do a convergence test; and do it if yes.
-      if (convergenceThreshold > 0) {
-
-        val rmse = (drmA - drmU %*% drmV.t).norm / sqrt(drmA.ncol * drmA.nrow)
-
-        if (i > 0) {
-          val rmsePrev = rmseIterations.last
-          val convergence = (rmsePrev - rmse) / rmsePrev
-
-          if (convergence < 0) {
-            log.warn("Rmse increase of %f. Should not happen.".format(convergence))
-            // I guess error growth can happen in ideal data case?
-            stop = true
-          } else if (convergence < convergenceThreshold) {
-            stop = true
-          }
-        }
-        rmseIterations :+= rmse
-      }
-
-      i += 1
-    }
-
-    new Result(drmU, drmV, rmseIterations)
-  }
-
-
-}

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/decompositions/DQR.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/decompositions/DQR.scala b/math-scala/src/main/scala/org/apache/mahout/math/decompositions/DQR.scala
deleted file mode 100644
index 389eba0..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/decompositions/DQR.scala
+++ /dev/null
@@ -1,78 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math.decompositions
-
-import org.apache.mahout.logging._
-import org.apache.mahout.math.Matrix
-import org.apache.mahout.math.scalabindings._
-import RLikeOps._
-import org.apache.mahout.math.drm._
-import RLikeDrmOps._
-
-object DQR {
-
-  private final implicit val log = getLog(DQR.getClass)
-
-  /**
-   * Distributed _thin_ QR. A'A must fit in a memory, i.e. if A is m x n, then n should be pretty
-   * controlled (<5000 or so). <P>
-   *
-   * It is recommended to checkpoint A since it does two passes over it. <P>
-   *
-   * It also guarantees that Q is partitioned exactly the same way (and in same key-order) as A, so
-   * their RDD should be able to zip successfully.
-   */
-  def dqrThin[K](drmA: DrmLike[K],
-                 checkRankDeficiency: Boolean = true,
-                 cacheHint: CacheHint.CacheHint = CacheHint.MEMORY_ONLY): (DrmLike[K], Matrix) = {
-
-    // Some mapBlock() calls need it
-    implicit val ktag =  drmA.keyClassTag
-
-    if (drmA.ncol > 5000)
-      warn("A is too fat. A'A must fit in memory and easily broadcasted.")
-
-    implicit val ctx = drmA.context
-
-    val AtA = (drmA.t %*% drmA).checkpoint(cacheHint)
-    val inCoreAtA = AtA.collect
-
-    trace("A'A=\n%s\n".format(inCoreAtA))
-
-    val ch = chol(inCoreAtA)
-    val inCoreR = (ch.getL cloned) t
-
-    trace("R=\n%s\n".format(inCoreR))
-
-    if (checkRankDeficiency && !ch.isPositiveDefinite)
-      throw new IllegalArgumentException("R is rank-deficient.")
-
-    val bcastAtA = drmBroadcast(inCoreAtA)
-
-    // Unfortunately, I don't think Cholesky decomposition is serializable to backend. So we re-
-    // decompose A'A in the backend again.
-
-    // Compute Q = A*inv(L') -- we can do it blockwise.
-    val Q = drmA.mapBlock() {
-      case (keys, block) => keys -> chol(bcastAtA).solveRight(block)
-    }
-
-    Q -> inCoreR
-  }
-
-}

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/decompositions/DSPCA.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/decompositions/DSPCA.scala b/math-scala/src/main/scala/org/apache/mahout/math/decompositions/DSPCA.scala
deleted file mode 100644
index 2c010bb..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/decompositions/DSPCA.scala
+++ /dev/null
@@ -1,162 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math.decompositions
-
-import org.apache.mahout.math.{Matrices, Vector}
-import org.apache.mahout.math.scalabindings._
-import RLikeOps._
-import org.apache.mahout.math.drm._
-import RLikeDrmOps._
-import org.apache.mahout.common.RandomUtils
-
-object DSPCA {
-
-  /**
-   * Distributed Stochastic PCA decomposition algorithm. A logical reflow of the "SSVD-PCA options.pdf"
-   * document of the MAHOUT-817.
-   *
-   * @param drmA input matrix A
-   * @param k request SSVD rank
-   * @param p oversampling parameter
-   * @param q number of power iterations (hint: use either 0 or 1)
-   * @return (U,V,s). Note that U, V are non-checkpointed matrices (i.e. one needs to actually use them
-   *         e.g. save them to hdfs in order to trigger their computation.
-   */
-  def dspca[K](drmA: DrmLike[K],
-               k: Int,
-               p: Int = 15,
-               q: Int = 0,
-               cacheHint: CacheHint.CacheHint = CacheHint.MEMORY_ONLY):
-  (DrmLike[K], DrmLike[Int], Vector) = {
-
-    // Some mapBlock() calls need it
-    implicit val ktag =  drmA.keyClassTag
-
-    val drmAcp = drmA.checkpoint(cacheHint)
-    implicit val ctx = drmAcp.context
-
-    val m = drmAcp.nrow
-    val n = drmAcp.ncol
-    assert(k <= (m min n), "k cannot be greater than smaller of m, n.")
-    val pfxed = safeToNonNegInt((m min n) - k min p)
-
-    // Actual decomposition rank
-    val r = k + pfxed
-
-    // Dataset mean
-    val mu = drmAcp.colMeans
-
-    val mtm = mu dot mu
-
-    // We represent Omega by its seed.
-    val omegaSeed = RandomUtils.getRandom().nextInt()
-    val omega = Matrices.symmetricUniformView(n, r, omegaSeed)
-
-    // This done in front in a single-threaded fashion for now. Even though it doesn't require any
-    // memory beyond that is required to keep xi around, it still might be parallelized to backs
-    // for significantly big n and r. TODO
-    val s_o = omega.t %*% mu
-
-    val bcastS_o = drmBroadcast(s_o)
-    val bcastMu = drmBroadcast(mu)
-
-    var drmY = drmAcp.mapBlock(ncol = r) {
-      case (keys, blockA) ⇒
-        val s_o:Vector = bcastS_o
-        val blockY = blockA %*% Matrices.symmetricUniformView(n, r, omegaSeed)
-        for (row ← 0 until blockY.nrow) blockY(row, ::) -= s_o
-        keys → blockY
-    }
-        // Checkpoint Y
-        .checkpoint(cacheHint)
-
-    var drmQ = dqrThin(drmY, checkRankDeficiency = false)._1.checkpoint(cacheHint)
-
-    var s_q = drmQ.colSums()
-    var bcastVarS_q = drmBroadcast(s_q)
-
-    // This actually should be optimized as identically partitioned map-side A'B since A and Q should
-    // still be identically partitioned.
-    var drmBt = (drmAcp.t %*% drmQ).checkpoint(cacheHint)
-
-    var s_b = (drmBt.t %*% mu).collect(::, 0)
-    var bcastVarS_b = drmBroadcast(s_b)
-
-    for (i ← 0 until q) {
-
-      // These closures don't seem to live well with outside-scope vars. This doesn't record closure
-      // attributes correctly. So we create additional set of vals for broadcast vars to properly 
-      // create readonly closure attributes in this very scope.
-      val bcastS_q = bcastVarS_q
-      val bcastMuInner = bcastMu
-
-      // Fix Bt as B' -= xi cross s_q
-      drmBt = drmBt.mapBlock() {
-        case (keys, block) ⇒
-          val s_q: Vector = bcastS_q
-          val mu: Vector = bcastMuInner
-          keys.zipWithIndex.foreach {
-            case (key, idx) ⇒ block(idx, ::) -= s_q * mu(key)
-          }
-          keys → block
-      }
-
-      drmY.uncache()
-      drmQ.uncache()
-
-      val bCastSt_b = drmBroadcast(s_b -=: mtm * s_q)
-
-      drmY = (drmAcp %*% drmBt)
-          // Fix Y by subtracting st_b from each row of the AB'
-          .mapBlock() {
-        case (keys, block) ⇒
-          val st_b: Vector = bCastSt_b
-          block := { (_, c, v) ⇒ v - st_b(c) }
-          keys → block
-      }
-          // Checkpoint Y
-          .checkpoint(cacheHint)
-
-      drmQ = dqrThin(drmY, checkRankDeficiency = false)._1.checkpoint(cacheHint)
-
-      s_q = drmQ.colSums()
-      bcastVarS_q = drmBroadcast(s_q)
-
-      // This on the other hand should be inner-join-and-map A'B optimization since A and Q_i are not
-      // identically partitioned anymore.
-      drmBt = (drmAcp.t %*% drmQ).checkpoint(cacheHint)
-
-      s_b = (drmBt.t %*% mu).collect(::, 0)
-      bcastVarS_b = drmBroadcast(s_b)
-    }
-
-    val c = s_q cross s_b
-    val inCoreBBt = (drmBt.t %*% drmBt).checkpoint(cacheHint).collect -=:
-        c -=: c.t +=: mtm *=: (s_q cross s_q)
-    val (inCoreUHat, d) = eigen(inCoreBBt)
-    val s = d.sqrt
-
-    // Since neither drmU nor drmV are actually computed until actually used, we don't need the flags
-    // instructing compute (or not compute) either of the U,V outputs anymore. Neat, isn't it?
-    val drmU = drmQ %*% inCoreUHat
-    val drmV = drmBt %*% (inCoreUHat %*% diagv(1 / s))
-
-    (drmU(::, 0 until k), drmV(::, 0 until k), s(0 until k))
-  }
-
-}

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/decompositions/DSSVD.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/decompositions/DSSVD.scala b/math-scala/src/main/scala/org/apache/mahout/math/decompositions/DSSVD.scala
deleted file mode 100644
index d917d11..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/decompositions/DSSVD.scala
+++ /dev/null
@@ -1,100 +0,0 @@
-package org.apache.mahout.math.decompositions
-
-import org.apache.mahout.math.{Matrices, Matrix, Vector}
-import org.apache.mahout.math.scalabindings._
-import RLikeOps._
-import org.apache.mahout.math.drm._
-import RLikeDrmOps._
-import org.apache.mahout.common.RandomUtils
-import org.apache.mahout.logging._
-
-object DSSVD {
-
-  private final implicit val log = getLog(DSSVD.getClass)
-
-  /**
-   * Distributed Stochastic Singular Value decomposition algorithm.
-   *
-   * @param drmA input matrix A
-   * @param k request SSVD rank
-   * @param p oversampling parameter
-   * @param q number of power iterations
-   * @return (U,V,s). Note that U, V are non-checkpointed matrices (i.e. one needs to actually use them
-   *         e.g. save them to hdfs in order to trigger their computation.
-   */
-  def dssvd[K](drmA: DrmLike[K],
-               k: Int,
-               p: Int = 15,
-               q: Int = 0,
-               cacheHint: CacheHint.CacheHint = CacheHint.MEMORY_ONLY):
-
-  (DrmLike[K], DrmLike[Int], Vector) = {
-
-    // Some mapBlock() calls need it
-    implicit val ktag =  drmA.keyClassTag
-
-    val drmAcp = drmA.checkpoint(cacheHint)
-
-    val m = drmAcp.nrow
-    val n = drmAcp.ncol
-    assert(k <= (m min n), "k cannot be greater than smaller of m, n.")
-    val pfxed = safeToNonNegInt((m min n) - k min p)
-
-    // Actual decomposition rank
-    val r = k + pfxed
-
-    // We represent Omega by its seed.
-    val omegaSeed = RandomUtils.getRandom().nextInt()
-
-    // Compute Y = A*Omega. Instead of redistributing view, we redistribute the Omega seed only and
-    // instantiate the Omega random matrix view in the backend instead. That way serialized closure
-    // is much more compact.
-    var drmY = drmAcp.mapBlock(ncol = r) {
-      case (keys, blockA) ⇒
-        val blockY = blockA %*% Matrices.symmetricUniformView(n, r, omegaSeed)
-        keys → blockY
-    }.checkpoint(cacheHint)
-
-    var drmQ = dqrThin(drmY)._1
-    // Checkpoint Q if last iteration
-    if (q == 0) drmQ = drmQ.checkpoint(cacheHint)
-
-    trace(s"dssvd:drmQ=${drmQ.collect}.")
-
-    // This actually should be optimized as identically partitioned map-side A'B since A and Q should
-    // still be identically partitioned.
-    var drmBt = drmAcp.t %*% drmQ
-    // Checkpoint B' if last iteration
-    if (q == 0) drmBt = drmBt.checkpoint(cacheHint)
-
-    trace(s"dssvd:drmB'=${drmBt.collect}.")
-
-    for (i ← 0  until q) {
-      drmY = drmAcp %*% drmBt
-      drmQ = dqrThin(drmY.checkpoint(cacheHint))._1
-      // Checkpoint Q if last iteration
-      if (i == q - 1) drmQ = drmQ.checkpoint(cacheHint)
-
-      // This on the other hand should be inner-join-and-map A'B optimization since A and Q_i are not
-      // identically partitioned anymore.`
-      drmBt = drmAcp.t %*% drmQ
-      // Checkpoint B' if last iteration
-      if (i == q - 1) drmBt = drmBt.checkpoint(cacheHint)
-    }
-
-    val mxBBt:Matrix = drmBt.t %*% drmBt
-
-    trace(s"dssvd: BB'=$mxBBt.")
-
-    val (inCoreUHat, d) = eigen(mxBBt)
-    val s = d.sqrt
-
-    // Since neither drmU nor drmV are actually computed until actually used, we don't need the flags
-    // instructing compute (or not compute) either of the U,V outputs anymore. Neat, isn't it?
-    val drmU = drmQ %*% inCoreUHat
-    val drmV = drmBt %*% (inCoreUHat %*%: diagv(1 /: s))
-
-    (drmU(::, 0 until k), drmV(::, 0 until k), s(0 until k))
-  }
-
-}

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/decompositions/SSVD.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/decompositions/SSVD.scala b/math-scala/src/main/scala/org/apache/mahout/math/decompositions/SSVD.scala
deleted file mode 100644
index fba9517..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/decompositions/SSVD.scala
+++ /dev/null
@@ -1,167 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math.decompositions
-
-import scala.math._
-import org.apache.mahout.math.{Matrices, Matrix}
-import org.apache.mahout.common.RandomUtils
-import org.apache.log4j.Logger
-import org.apache.mahout.math.scalabindings._
-import RLikeOps._
-
-private[math] object SSVD {
-
-  private val log = Logger.getLogger(SSVD.getClass)
-
-  /**
-   * In-core SSVD algorithm.
-   *
-   * @param a input matrix A
-   * @param k request SSVD rank
-   * @param p oversampling parameter
-   * @param q number of power iterations
-   * @return (U,V,s)
-   */
-  def ssvd(a: Matrix, k: Int, p: Int = 15, q: Int = 0) = {
-    val m = a.nrow
-    val n = a.ncol
-    if (k > min(m, n))
-      throw new IllegalArgumentException(
-        "k cannot be greater than smaller of m,n")
-    val pfxed = min(p, min(m, n) - k)
-
-    // Actual decomposition rank
-    val r = k + pfxed
-
-    val rnd = RandomUtils.getRandom
-    val omega = Matrices.symmetricUniformView(n, r, rnd.nextInt)
-
-    var y = a %*% omega
-    var yty = y.t %*% y
-    val at = a.t
-    var ch = chol(yty)
-    assert(ch.isPositiveDefinite, "Rank-deficiency detected during s-SVD")
-    var bt = ch.solveRight(at %*% y)
-
-    // Power iterations
-    for (i ← 0 until q) {
-      y = a %*% bt
-      yty = y.t %*% y
-      ch = chol(yty)
-      bt = ch.solveRight(at %*% y)
-    }
-
-    val bbt = bt.t %*% bt
-    val (uhat, d) = eigen(bbt)
-
-    val s = d.sqrt
-    val u = ch.solveRight(y) %*% uhat
-    val v = bt %*% (uhat %*% diagv(1 /: s))
-
-    (u(::, 0 until k), v(::, 0 until k), s(0 until k))
-  }
-
-  /**
-   * PCA based on SSVD that runs without forming an always-dense A-(colMeans(A)) input for SVD. This
-   * follows the solution outlined in MAHOUT-817. For in-core version it, for most part, is supposed
-   * to save some memory for sparse inputs by removing direct mean subtraction.<P>
-   *
-   * Hint: Usually one wants to use AV which is approsimately USigma, i.e.<code>u %*%: diagv(s)</code>.
-   * If retaining distances and orignal scaled variances not that important, the normalized PCA space
-   * is just U.
-   *
-   * Important: data points are considered to be rows.
-   *
-   * @param a input matrix A
-   * @param k request SSVD rank
-   * @param p oversampling parameter
-   * @param q number of power iterations
-   * @return (U,V,s)
-   */
-  def spca(a:Matrix, k: Int, p: Int = 15, q: Int = 0) = {
-    val m = a.nrow
-    val n = a.ncol
-    if (k > min(m, n))
-      throw new IllegalArgumentException(
-        "k cannot be greater than smaller of m,n")
-    val pfxed = min(p, min(m, n) - k)
-
-    // Actual decomposition rank
-    val r = k + pfxed
-
-    val rnd = RandomUtils.getRandom
-    val omega = Matrices.symmetricUniformView(n, r, rnd.nextInt)
-
-    // Dataset mean
-    val mu = a.colMeans()
-    val mtm = mu dot mu
-
-    if (log.isDebugEnabled) log.debug("xi=%s".format(mu))
-
-    var y = a %*% omega
-
-    // Fixing y
-    val s_o = omega.t %*% mu
-    y := ((r,c,v) ⇒ v - s_o(c))
-
-    var yty = y.t %*% y
-    var ch = chol(yty)
-//    assert(ch.isPositiveDefinite, "Rank-deficiency detected during s-SVD")
-
-    // This is implicit Q of QR(Y)
-    var qm = ch.solveRight(y)
-    var bt = a.t %*% qm
-    var s_q = qm.colSums()
-    var s_b = bt.t %*% mu
-
-    // Power iterations
-    for (i ← 0 until q) {
-
-      // Fix bt
-      bt -= mu cross s_q
-
-      y = a %*% bt
-
-      // Fix Y again.
-      val st_b = s_b -=: mtm * s_q
-      y := ((r,c,v) ⇒ v - st_b(c))
-
-      yty = y.t %*% y
-      ch = chol(yty)
-      qm = ch.solveRight(y)
-      bt = a.t %*% qm
-      s_q = qm.colSums()
-      s_b = bt.t %*% mu
-    }
-
-    val c = s_q cross s_b
-
-    // BB' computation becomes
-    val bbt = bt.t %*% bt -= c -= c.t += (mtm * s_q cross s_q)
-
-    val (uhat, d) = eigen(bbt)
-
-    val s = d.sqrt
-    val u = qm %*% uhat
-    val v = bt %*% (uhat %*%: diagv(1 /: s))
-
-    (u(::, 0 until k), v(::, 0 until k), s(0 until k))
-
-  }
-
-}

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/decompositions/package.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/decompositions/package.scala b/math-scala/src/main/scala/org/apache/mahout/math/decompositions/package.scala
deleted file mode 100644
index a7b829f..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/decompositions/package.scala
+++ /dev/null
@@ -1,141 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math
-
-import scala.reflect.ClassTag
-import org.apache.mahout.math.drm.DrmLike
-
-/**
- * This package holds all decomposition and factorization-like methods, all that we were able to make
- * distributed engine-independent so far, anyway.
- */
-package object decompositions {
-
-  // ================ In-core decompositions ===================
-
-  /**
-   * In-core SSVD algorithm.
-   *
-   * @param a input matrix A
-   * @param k request SSVD rank
-   * @param p oversampling parameter
-   * @param q number of power iterations
-   * @return (U,V,s)
-   */
-  def ssvd(a: Matrix, k: Int, p: Int = 15, q: Int = 0) = SSVD.ssvd(a, k, p, q)
-
-  /**
-   * PCA based on SSVD that runs without forming an always-dense A-(colMeans(A)) input for SVD. This
-   * follows the solution outlined in MAHOUT-817. For in-core version it, for most part, is supposed
-   * to save some memory for sparse inputs by removing direct mean subtraction.<P>
-   *
-   * Hint: Usually one wants to use AV which is approsimately USigma, i.e.<code>u %*%: diagv(s)</code>.
-   * If retaining distances and orignal scaled variances not that important, the normalized PCA space
-   * is just U.
-   *
-   * Important: data points are considered to be rows.
-   *
-   * @param a input matrix A
-   * @param k request SSVD rank
-   * @param p oversampling parameter
-   * @param q number of power iterations
-   * @return (U,V,s)
-   */
-  def spca(a: Matrix, k: Int, p: Int = 15, q: Int = 0) =
-    SSVD.spca(a = a, k = k, p = p, q = q)
-
-  // ============== Distributed decompositions ===================
-
-  /**
-   * Distributed _thin_ QR. A'A must fit in a memory, i.e. if A is m x n, then n should be pretty
-   * controlled (<5000 or so). <P>
-   *
-   * It is recommended to checkpoint A since it does two passes over it. <P>
-   *
-   * It also guarantees that Q is partitioned exactly the same way (and in same key-order) as A, so
-   * their RDD should be able to zip successfully.
-   */
-  def dqrThin[K: ClassTag](drmA: DrmLike[K], checkRankDeficiency: Boolean = true): (DrmLike[K], Matrix) =
-    DQR.dqrThin(drmA, checkRankDeficiency)
-
-  /**
-   * Distributed Stochastic Singular Value decomposition algorithm.
-   *
-   * @param drmA input matrix A
-   * @param k request SSVD rank
-   * @param p oversampling parameter
-   * @param q number of power iterations
-   * @return (U,V,s). Note that U, V are non-checkpointed matrices (i.e. one needs to actually use them
-   *         e.g. save them to hdfs in order to trigger their computation.
-   */
-  def dssvd[K: ClassTag](drmA: DrmLike[K], k: Int, p: Int = 15, q: Int = 0):
-  (DrmLike[K], DrmLike[Int], Vector) = DSSVD.dssvd(drmA, k, p, q)
-
-  /**
-   * Distributed Stochastic PCA decomposition algorithm. A logical reflow of the "SSVD-PCA options.pdf"
-   * document of the MAHOUT-817.
-   *
-   * @param drmA input matrix A
-   * @param k request SSVD rank
-   * @param p oversampling parameter
-   * @param q number of power iterations (hint: use either 0 or 1)
-   * @return (U,V,s). Note that U, V are non-checkpointed matrices (i.e. one needs to actually use them
-   *         e.g. save them to hdfs in order to trigger their computation.
-   */
-  def dspca[K: ClassTag](drmA: DrmLike[K], k: Int, p: Int = 15, q: Int = 0):
-  (DrmLike[K], DrmLike[Int], Vector) = DSPCA.dspca(drmA, k, p, q)
-
-  /** Result for distributed ALS-type two-component factorization algorithms */
-  type FactorizationResult[K] = ALS.Result[K]
-
-  /** Result for distributed ALS-type two-component factorization algorithms, in-core matrices */
-  type FactorizationResultInCore = ALS.InCoreResult
-  
-  /**
-   * Run ALS.
-   * <P>
-   *
-   * Example:
-   *
-   * <pre>
-   * val (u,v,errors) = als(input, k).toTuple
-   * </pre>
-   *
-   * ALS runs until (rmse[i-1]-rmse[i])/rmse[i-1] < convergenceThreshold, or i==maxIterations,
-   * whichever earlier.
-   * <P>
-   *
-   * @param drmA The input matrix
-   * @param k required rank of decomposition (number of cols in U and V results)
-   * @param convergenceThreshold stop sooner if (rmse[i-1] - rmse[i])/rmse[i - 1] is less than this
-   *                             value. If <=0 then we won't compute RMSE and use convergence test.
-   * @param lambda regularization rate
-   * @param maxIterations maximum iterations to run regardless of convergence
-   * @tparam K row key type of the input (100 is probably more than enough)
-   * @return { @link org.apache.mahout.math.drm.decompositions.ALS.Result}
-   */
-  def dals[K: ClassTag](
-      drmA: DrmLike[K],
-      k: Int = 50,
-      lambda: Double = 0.0,
-      maxIterations: Int = 10,
-      convergenceThreshold: Double = 0.10
-      ): FactorizationResult[K] =
-    ALS.dals(drmA, k, lambda, maxIterations, convergenceThreshold)
-
-}

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/drm/BCast.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/drm/BCast.scala b/math-scala/src/main/scala/org/apache/mahout/math/drm/BCast.scala
deleted file mode 100644
index b86e286..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/drm/BCast.scala
+++ /dev/null
@@ -1,24 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math.drm
-
-/** Broadcast variable abstraction */
-trait BCast[T] extends java.io.Closeable {
-  def value:T
-
-}

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/drm/CacheHint.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/drm/CacheHint.scala b/math-scala/src/main/scala/org/apache/mahout/math/drm/CacheHint.scala
deleted file mode 100644
index 3755f31..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/drm/CacheHint.scala
+++ /dev/null
@@ -1,36 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math.drm
-
-object CacheHint extends Enumeration {
-
-  type CacheHint = Value
-
-  val NONE,
-  DISK_ONLY,
-  DISK_ONLY_2,
-  MEMORY_ONLY,
-  MEMORY_ONLY_2,
-  MEMORY_ONLY_SER,
-  MEMORY_ONLY_SER_2,
-  MEMORY_AND_DISK,
-  MEMORY_AND_DISK_2,
-  MEMORY_AND_DISK_SER,
-  MEMORY_AND_DISK_SER_2 = Value
-
-}

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/drm/CheckpointedDrm.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/drm/CheckpointedDrm.scala b/math-scala/src/main/scala/org/apache/mahout/math/drm/CheckpointedDrm.scala
deleted file mode 100644
index 31f8097..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/drm/CheckpointedDrm.scala
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math.drm
-
-import org.apache.mahout.math.Matrix
-import org.apache.mahout.math.drm.CacheHint.CacheHint
-
-/**
- * Checkpointed DRM API. This is a matrix that has optimized RDD lineage behind it and can be
- * therefore collected or saved.
- *
- * @tparam K matrix key type (e.g. the keys of sequence files once persisted)
- */
-trait CheckpointedDrm[K] extends DrmLike[K] {
-
-  def collect: Matrix
-
-  def dfsWrite(path: String)
-
-  val cacheHint: CacheHint
-
-  /** If this checkpoint is already declared cached, uncache. */
-  def uncache(): this.type
-
-  /** changes the number of rows without touching the underlying data */
-  def newRowCardinality(n: Int): CheckpointedDrm[K]
-
-}

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/drm/CheckpointedOps.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/drm/CheckpointedOps.scala b/math-scala/src/main/scala/org/apache/mahout/math/drm/CheckpointedOps.scala
deleted file mode 100644
index 37cd981..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/drm/CheckpointedOps.scala
+++ /dev/null
@@ -1,49 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math.drm
-
-import org.apache.mahout.math._
-
-import org.apache.mahout.math.scalabindings.RLikeOps._
-
-/**
- * Additional experimental operations over CheckpointedDRM implementation. I will possibly move them up to
- * the DRMBase once they stabilize.
- *
- */
-class CheckpointedOps[K](val drm: CheckpointedDrm[K]) {
-
-
-  /** Column sums. At this point this runs on checkpoint and collects in-core vector. */
-  def colSums(): Vector = drm.context.colSums(drm)
-
-  /** Column clounts. Counts the non-zero values. At this point this runs on checkpoint and collects in-core vector. */
-  def numNonZeroElementsPerColumn(): Vector = drm.context.numNonZeroElementsPerColumn(drm)
-
-  /** Column Means */
-  def colMeans(): Vector = drm.context.colMeans(drm)
-
-  /** Optional engine-specific all reduce tensor operation. */
-  def allreduceBlock(bmf: BlockMapFunc2[K], rf: BlockReduceFunc = _ += _): Matrix =
-
-    drm.context.allreduceBlock(drm, bmf, rf)
-
-  /** Second norm */
-  def norm():Double = drm.context.norm(drm)
-}
-

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/drm/DistributedContext.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/drm/DistributedContext.scala b/math-scala/src/main/scala/org/apache/mahout/math/drm/DistributedContext.scala
deleted file mode 100644
index e1833d8..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/drm/DistributedContext.scala
+++ /dev/null
@@ -1,27 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math.drm
-
-import java.io.Closeable
-
-/** Distributed context (a.k.a. distributed session handle) */
-trait DistributedContext extends Closeable {
-
-  val engine: DistributedEngine
-
-}

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/drm/DistributedEngine.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/drm/DistributedEngine.scala b/math-scala/src/main/scala/org/apache/mahout/math/drm/DistributedEngine.scala
deleted file mode 100644
index c27e8dd..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/drm/DistributedEngine.scala
+++ /dev/null
@@ -1,268 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math.drm
-
-import org.apache.mahout.math.indexeddataset._
-
-import logical._
-import org.apache.mahout.math._
-import scalabindings._
-import RLikeOps._
-import DistributedEngine._
-import org.apache.log4j.Logger
-
-import scala.reflect.ClassTag
-
-/** Abstraction of optimizer/distributed engine */
-trait DistributedEngine {
-
-  /**
-   * First optimization pass. Return physical plan that we can pass to exec(). This rewrite may
-   * introduce logical constructs (including engine-specific ones) that user DSL cannot even produce
-   * per se.
-   * <P>
-   *
-   * A particular physical engine implementation may choose to either use the default rewrites or
-   * build its own rewriting rules.
-   * <P>
-   */
-  def optimizerRewrite[K: ClassTag](action: DrmLike[K]): DrmLike[K] = pass3(pass2(pass1(action)))
-
-  /** Second optimizer pass. Translate previously rewritten logical pipeline into physical engine plan. */
-  def toPhysical[K: ClassTag](plan: DrmLike[K], ch: CacheHint.CacheHint): CheckpointedDrm[K]
-
-  /** Engine-specific colSums implementation based on a checkpoint. */
-  def colSums[K](drm: CheckpointedDrm[K]): Vector
-
-  /** Optional engine-specific all reduce tensor operation. */
-  def allreduceBlock[K](drm: CheckpointedDrm[K], bmf: BlockMapFunc2[K], rf: BlockReduceFunc): Matrix
-
-  /** Engine-specific numNonZeroElementsPerColumn implementation based on a checkpoint. */
-  def numNonZeroElementsPerColumn[K](drm: CheckpointedDrm[K]): Vector
-
-  /** Engine-specific colMeans implementation based on a checkpoint. */
-  def colMeans[K](drm: CheckpointedDrm[K]): Vector
-
-  def norm[K](drm: CheckpointedDrm[K]): Double
-
-  /** Broadcast support */
-  def drmBroadcast(v: Vector)(implicit dc: DistributedContext): BCast[Vector]
-
-  /** Broadcast support */
-  def drmBroadcast(m: Matrix)(implicit dc: DistributedContext): BCast[Matrix]
-
-  /**
-   * Load DRM from hdfs (as in Mahout DRM format).
-   * <P/>
-   * @param path The DFS path to load from
-   * @param parMin Minimum parallelism after load (equivalent to #par(min=...)).
-   */
-  def drmDfsRead(path: String, parMin: Int = 0)(implicit sc: DistributedContext): CheckpointedDrm[_]
-
-  /** Parallelize in-core matrix as the backend engine distributed matrix, using row ordinal indices as data set keys. */
-  def drmParallelizeWithRowIndices(m: Matrix, numPartitions: Int = 1)(implicit sc: DistributedContext):
-  CheckpointedDrm[Int]
-
-  /** Parallelize in-core matrix as the backend engine distributed matrix, using row labels as a data set keys. */
-  def drmParallelizeWithRowLabels(m: Matrix, numPartitions: Int = 1)(implicit sc: DistributedContext):
-  CheckpointedDrm[String]
-
-  /** This creates an empty DRM with specified number of partitions and cardinality. */
-  def drmParallelizeEmpty(nrow: Int, ncol: Int, numPartitions: Int = 10)(implicit sc: DistributedContext):
-  CheckpointedDrm[Int]
-
-  /** Creates empty DRM with non-trivial height */
-  def drmParallelizeEmptyLong(nrow: Long, ncol: Int, numPartitions: Int = 10)(implicit sc: DistributedContext):
-  CheckpointedDrm[Long]
-
-  /**
-   * Convert non-int-keyed matrix to an int-keyed, computing optionally mapping from old keys
-   * to row indices in the new one. The mapping, if requested, is returned as a 1-column matrix.
-   */
-  def drm2IntKeyed[K](drmX: DrmLike[K], computeMap: Boolean = false): (DrmLike[Int], Option[DrmLike[K]])
-
-  /**
-   * (Optional) Sampling operation. Consistent with Spark semantics of the same.
-   * @param drmX
-   * @param fraction
-   * @param replacement
-   * @tparam K
-   * @return
-   */
-  def drmSampleRows[K](drmX: DrmLike[K], fraction: Double, replacement: Boolean = false): DrmLike[K]
-
-  def drmSampleKRows[K](drmX: DrmLike[K], numSamples:Int, replacement:Boolean = false) : Matrix
-
-  /**
-   * Load IndexedDataset from text delimited format.
-   * @param src comma delimited URIs to read from
-   * @param schema defines format of file(s)
-   */
-  def indexedDatasetDFSRead(src: String,
-      schema: Schema = DefaultIndexedDatasetReadSchema,
-      existingRowIDs: Option[BiDictionary] = None)
-      (implicit sc: DistributedContext):
-    IndexedDataset
-
-  /**
-   * Load IndexedDataset from text delimited format, one element per line
-   * @param src comma delimited URIs to read from
-   * @param schema defines format of file(s)
-   */
-  def indexedDatasetDFSReadElements(src: String,
-      schema: Schema = DefaultIndexedDatasetElementReadSchema,
-      existingRowIDs: Option[BiDictionary] = None)
-      (implicit sc: DistributedContext):
-    IndexedDataset
-
-}
-
-object DistributedEngine {
-
-  private val log = Logger.getLogger(DistributedEngine.getClass)
-
-  /** This is mostly multiplication operations rewrites */
-  private def pass1[K](action: DrmLike[K]): DrmLike[K] = {
-
-    action match {
-
-      // Logical but previously had checkpoint attached to it already that has some caching policy to it
-      case cpa: CheckpointAction[K] if cpa.cp.exists(_.cacheHint != CacheHint.NONE) ⇒ cpa.cp.get
-
-      // self element-wise rewrite
-      case OpAewB(a, b, op) if a == b => {
-        op match {
-          case "*" ⇒ OpAewUnaryFunc(pass1(a), (x) ⇒ x * x)
-          case "/" ⇒ OpAewUnaryFunc(pass1(a), (x) ⇒ x / x)
-          // Self "+" and "-" don't make a lot of sense, but we do include it for completeness.
-          case "+" ⇒ OpAewUnaryFunc(pass1(a), 2.0 * _)
-          case "-" ⇒ OpAewUnaryFunc(pass1(a), (_) ⇒ 0.0)
-          case _ ⇒
-          require(false, s"Unsupported operator $op")
-            null
-        }
-      }
-      case OpAB(OpAt(a), b) if a == b ⇒ OpAtA(pass1(a))
-      case OpABAnyKey(OpAtAnyKey(a), b) if a == b ⇒ OpAtA(pass1(a))
-
-      // A small rule change: Now that we have removed ClassTag at the %*% operation, it doesn't
-      // match b[Int] case automatically any longer. So, we need to check and rewrite it dynamically
-      // and re-run pass1 again on the obtained tree.
-      case OpABAnyKey(a, b) if b.keyClassTag == ClassTag.Int ⇒ pass1(OpAB(a, b.asInstanceOf[DrmLike[Int]]))
-      case OpAtAnyKey(a) if a.keyClassTag == ClassTag.Int ⇒ pass1(OpAt(a.asInstanceOf[DrmLike[Int]]))
-
-      // For now, rewrite left-multiply via transpositions, i.e.
-      // inCoreA %*% B = (B' %*% inCoreA')'
-      case op@OpTimesLeftMatrix(a, b) ⇒
-        OpAt(OpTimesRightMatrix(A = OpAt(pass1(b)), right = a.t))
-
-      // Add vertical row index concatenation for rbind() on DrmLike[Int] fragments
-      case op@OpRbind(a, b) if op.keyClassTag == ClassTag.Int ⇒
-
-        // Make sure closure sees only local vals, not attributes. We need to do these ugly casts
-        // around because compiler could not infer that K is the same as Int, based on if() above.
-        val ma = safeToNonNegInt(a.nrow)
-        val bAdjusted = new OpMapBlock[Int, Int](A = pass1(b.asInstanceOf[DrmLike[Int]]), bmf = {
-          case (keys, block) ⇒ keys.map(_ + ma) → block
-        }, identicallyPartitioned = false)
-        val aAdjusted = a.asInstanceOf[DrmLike[Int]]
-        OpRbind(pass1(aAdjusted), bAdjusted).asInstanceOf[DrmLike[K]]
-
-      // Stop at checkpoints
-      case cd: CheckpointedDrm[_] ⇒ action
-
-      // For everything else we just pass-thru the operator arguments to optimizer
-      case uop: AbstractUnaryOp[_, K] ⇒
-        uop.A = pass1(uop.A)
-        uop
-
-      case bop: AbstractBinaryOp[_, _, K] ⇒
-        bop.A = pass1(bop.A)
-        bop.B = pass1(bop.B)
-        bop
-    }
-  }
-
-  /** This would remove stuff like A.t.t that previous step may have created */
-  private def pass2[K](action: DrmLike[K]): DrmLike[K] = {
-    action match {
-
-      // Fusion of unary funcs into single, like 1 + x * x.
-      // Since we repeating the pass over self after rewrite, we dont' need to descend into arguments
-      // recursively here.
-      case op1@OpAewUnaryFunc(op2@OpAewUnaryFunc(a, _, _), _, _) ⇒
-        pass2(OpAewUnaryFuncFusion(a, op1 :: op2 :: Nil))
-
-      // Fusion one step further, like 1 + 2 * x * x. All should be rewritten as one UnaryFuncFusion.
-      // Since we repeating the pass over self after rewrite, we dont' need to descend into arguments
-      // recursively here.
-      case op@OpAewUnaryFuncFusion(op2@OpAewUnaryFunc(a, _, _), _) ⇒
-        pass2(OpAewUnaryFuncFusion(a, op.ff :+ op2))
-
-      // A.t.t => A
-      case OpAt(top@OpAt(a)) ⇒  pass2(a)
-
-      // Stop at checkpoints
-      case cd: CheckpointedDrm[_] ⇒  action
-
-      // For everything else we just pass-thru the operator arguments to optimizer
-      case uop: AbstractUnaryOp[_, K] ⇒
-        uop.A = pass2(uop.A)
-        uop
-      case bop: AbstractBinaryOp[_, _, K] ⇒
-        bop.A = pass2(bop.A)
-        bop.B = pass2(bop.B)
-        bop
-    }
-  }
-
-  /** Some further rewrites that are conditioned on A.t.t removal */
-  private def pass3[K](action: DrmLike[K]): DrmLike[K] = {
-    action match {
-
-      // matrix products.
-      case OpAB(a, OpAt(b)) ⇒  OpABt(pass3(a), pass3(b))
-
-      // AtB cases that make sense.
-      case OpAB(OpAt(a), b) if a.partitioningTag == b.partitioningTag ⇒  OpAtB(pass3(a), pass3(b))
-      case OpABAnyKey(OpAtAnyKey(a), b) ⇒  OpAtB(pass3(a), pass3(b))
-
-      // Need some cost to choose between the following.
-
-      case OpAB(OpAt(a), b) ⇒  OpAtB(pass3(a), pass3(b))
-      //      case OpAB(OpAt(a), b) => OpAt(OpABt(OpAt(pass1(b)), pass1(a)))
-      case OpAB(a, b) ⇒  OpABt(pass3(a), OpAt(pass3(b)))
-
-      // Rewrite A'x
-      case op@OpAx(op1@OpAt(a), x) ⇒  OpAtx(pass3(a), x)
-
-      // Stop at checkpoints
-      case cd: CheckpointedDrm[_] ⇒  action
-
-      // For everything else we just pass-thru the operator arguments to optimizer
-      case uop: AbstractUnaryOp[_, K] ⇒
-        uop.A = pass3(uop.A)
-        uop
-      case bop: AbstractBinaryOp[_, _, K] ⇒
-        bop.A = pass3(bop.A)
-        bop.B = pass3(bop.B)
-        bop
-    }
-  }
-
-}
\ No newline at end of file

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/drm/DrmDoubleScalarOps.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/drm/DrmDoubleScalarOps.scala b/math-scala/src/main/scala/org/apache/mahout/math/drm/DrmDoubleScalarOps.scala
deleted file mode 100644
index de03776..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/drm/DrmDoubleScalarOps.scala
+++ /dev/null
@@ -1,37 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math.drm
-
-import org.apache.mahout.math.drm.RLikeDrmOps._
-import org.apache.mahout.math.drm.logical.OpCbindScalar
-
-import scala.reflect.ClassTag
-
-class DrmDoubleScalarOps(val x:Double) extends AnyVal{
-
-  def +[K:ClassTag](that:DrmLike[K]) = that + x
-
-  def *[K:ClassTag](that:DrmLike[K]) = that * x
-
-  def -[K:ClassTag](that:DrmLike[K]) = x -: that
-
-  def /[K:ClassTag](that:DrmLike[K]) = x /: that
-
-  def cbind[K: ClassTag](that: DrmLike[K]) = OpCbindScalar(A = that, x = x, leftBind = true)
-
-}

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/drm/DrmLike.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/drm/DrmLike.scala b/math-scala/src/main/scala/org/apache/mahout/math/drm/DrmLike.scala
deleted file mode 100644
index 23f5fc6..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/drm/DrmLike.scala
+++ /dev/null
@@ -1,60 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math.drm
-
-import scala.reflect.ClassTag
-
-/**
- *
- * Basic DRM trait.
- *
- * Since we already call the package "sparkbindings", I will not use stem "spark" with classes in
- * this package. Spark backing is already implied.
- *
- */
-trait DrmLike[K] {
-
-  protected[mahout] def partitioningTag: Long
-
-  protected[mahout] def canHaveMissingRows: Boolean
-
-  /**
-   * Distributed context, can be implicitly converted to operations on [[org.apache.mahout.math.drm.
-   * DistributedEngine]].
-   */
-  val context:DistributedContext
-
-  /** R-like syntax for number of rows. */
-  def nrow: Long
-
-  /** R-like syntax for number of columns */
-  def ncol: Int
-
-  /**
-    * Explicit extraction of key class Tag since traits don't support context bound access; but actual
-    * implementation knows it
-    */
-  def keyClassTag: ClassTag[K]
-
-  /**
-   * Action operator -- does not necessary means Spark action; but does mean running BLAS optimizer
-   * and writing down Spark graph lineage since last checkpointed DRM.
-   */
-  def checkpoint(cacheHint: CacheHint.CacheHint = CacheHint.MEMORY_ONLY): CheckpointedDrm[K]
-
-}

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/drm/DrmLikeOps.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/drm/DrmLikeOps.scala b/math-scala/src/main/scala/org/apache/mahout/math/drm/DrmLikeOps.scala
deleted file mode 100644
index 43b4f56..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/drm/DrmLikeOps.scala
+++ /dev/null
@@ -1,140 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math.drm
-
-import scala.reflect.ClassTag
-import org.apache.mahout.math.scalabindings._
-import org.apache.mahout.math.drm.logical.{OpAewUnaryFunc, OpPar, OpMapBlock, OpRowRange}
-
-/** Common Drm ops */
-class DrmLikeOps[K](protected[drm] val drm: DrmLike[K]) {
-
-  /**
-   * Parallelism adjustments. <P/>
-   *
-   * Change only one of parameters from default value to choose new parallelism adjustment strategy.
-   * <P/>
-   *
-   * E.g. use
-   * <pre>
-   *   drmA.par(auto = true)
-   * </pre>
-   * to use automatic parallelism adjustment.
-   * <P/>
-   *
-   * Parallelism here in API is fairly abstract concept, and actual value interpretation is left for
-   * a particular backend strategy. However, it is usually equivalent to number of map tasks or data
-   * splits.
-   * <P/>
-   *
-   * @param min If changed from default, ensures the product has at least that much parallelism.
-   * @param exact if changed from default, ensures the pipeline product has exactly that much
-   *              parallelism.
-   * @param auto If changed from default, engine-specific automatic parallelism adjustment strategy
-   *             is applied.
-   */
-  def par(min: Int = -1, exact: Int = -1, auto: Boolean = false) = {
-    require(min > 0 || exact > 0 || auto, "Invalid argument")
-    OpPar(drm, minSplits = min, exactSplits = exact)
-  }
-
-  /**
-   * Map matrix block-wise vertically. Blocks of the new matrix can be modified original block
-   * matrices; or they could be completely new matrices with new keyset. In the latter case, output
-   * matrix width must be specified with <code>ncol</code> parameter.<P>
-   *
-   * New block heights must be of the same height as the original geometry.<P>
-   *
-   * @param ncol new matrix' width (only needed if width changes).
-   * @param bmf
-   * @tparam R
-   * @return
-   */
-  def mapBlock[R: ClassTag](ncol: Int = -1, identicallyPartitioned: Boolean = true)
-      (bmf: BlockMapFunc[K, R]): DrmLike[R] =
-    new OpMapBlock[K, R](
-      A = drm,
-      bmf = bmf,
-      _ncol = ncol,
-      identicallyPartitioned = identicallyPartitioned
-    )
-
-  /**
-   * Slicing the DRM. Should eventually work just like in-core drm (e.g. A(0 until 5, 5 until 15)).<P>
-   *
-   * The all-range is denoted by '::', e.g.: A(::, 0 until 5).<P>
-   *
-   * Row range is currently unsupported except for the all-range. When it will be fully supported,
-   * the input must be Int-keyed, i.e. of DrmLike[Int] type for non-all-range specifications.
-   *
-   * @param rowRange Row range. This must be '::' (all-range) unless matrix rows are keyed by Int key.
-   * @param colRange col range. Must be a sub-range of <code>0 until ncol</code>. '::' denotes all-range.
-   */
-  def apply(rowRange: Range, colRange: Range): DrmLike[K] = {
-
-    import RLikeDrmOps._
-    import RLikeOps._
-
-    implicit val ktag = drm.keyClassTag
-
-    val rowSrc: DrmLike[K] = if (rowRange != ::) {
-
-      if (ClassTag.Int == ktag) {
-
-        assert(rowRange.head >= 0 && rowRange.last < drm.nrow, "rows range out of range")
-        val intKeyed = drm.asInstanceOf[DrmLike[Int]]
-
-        new OpRowRange(A = intKeyed, rowRange = rowRange).asInstanceOf[DrmLike[K]]
-
-      } else throw new IllegalArgumentException("non-all row range is only supported for Int-keyed DRMs.")
-
-    } else drm
-
-    if (colRange != ::) {
-
-      assert(colRange.head >= 0 && colRange.last < drm.ncol, "col range out of range")
-
-      // Use mapBlock operator to do in-core subranging.
-      rowSrc.mapBlock(ncol = colRange.length)({
-        case (keys, block) => keys -> block(::, colRange)
-      })
-
-    } else rowSrc
-  }
-
-  /**
-    * Apply a function element-wise.
-    *
-    * @param f         element-wise function
-    * @param evalZeros Do we have to process zero elements? true, false, auto: if auto, we will test
-    *                  the supplied function for `f(0) != 0`, and depending on the result, will
-    *                  decide if we want evaluation for zero elements. WARNING: the AUTO setting
-    *                  may not always work correctly for functions that are meant to run in a specific
-    *                  backend context, or non-deterministic functions, such as {-1,0,1} random
-    *                  generators.
-    * @return new DRM with the element-wise function applied.
-    */
-  def apply(f: Double ⇒ Double, evalZeros: AutoBooleanEnum.T = AutoBooleanEnum.AUTO) = {
-    val ezeros = evalZeros match {
-      case AutoBooleanEnum.TRUE ⇒ true
-      case AutoBooleanEnum.FALSE ⇒ false
-      case AutoBooleanEnum.AUTO ⇒ f(0) != 0
-    }
-    new OpAewUnaryFunc[K](drm, f, ezeros)
-  }
-}

http://git-wip-us.apache.org/repos/asf/mahout/blob/e0573de3/math-scala/src/main/scala/org/apache/mahout/math/drm/RLikeDrmOps.scala
----------------------------------------------------------------------
diff --git a/math-scala/src/main/scala/org/apache/mahout/math/drm/RLikeDrmOps.scala b/math-scala/src/main/scala/org/apache/mahout/math/drm/RLikeDrmOps.scala
deleted file mode 100644
index 8bea741..0000000
--- a/math-scala/src/main/scala/org/apache/mahout/math/drm/RLikeDrmOps.scala
+++ /dev/null
@@ -1,172 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.mahout.math.drm
-
-import scala.reflect.ClassTag
-import collection._
-import JavaConversions._
-import org.apache.mahout.math.{Vector, Matrix}
-import org.apache.mahout.math.drm.logical._
-import org.apache.mahout.math.scalabindings._
-import RLikeOps._
-
-class RLikeDrmOps[K](drm: DrmLike[K]) extends DrmLikeOps[K](drm) {
-
-  import RLikeDrmOps._
-  import org.apache.mahout.math.scalabindings._
-
-  def +(that: DrmLike[K]): DrmLike[K] = OpAewB[K](A = this, B = that, op = "+")
-
-  def -(that: DrmLike[K]): DrmLike[K] = OpAewB[K](A = this, B = that, op = "-")
-
-  def *(that: DrmLike[K]): DrmLike[K] = OpAewB[K](A = this, B = that, op = "*")
-
-  def /(that: DrmLike[K]): DrmLike[K] = OpAewB[K](A = this, B = that, op = "/")
-
-  def +(that: Double): DrmLike[K] = OpAewUnaryFunc[K](A = this, f = _ + that, evalZeros = true)
-
-  def +:(that: Double): DrmLike[K] = OpAewUnaryFunc[K](A = this, f = that + _, evalZeros = true)
-
-  def -(that: Double): DrmLike[K] = OpAewUnaryFunc[K](A = this, f = _ - that, evalZeros = true)
-
-  def -:(that: Double): DrmLike[K] = OpAewUnaryFunc[K](A = this, f = that - _, evalZeros = true)
-
-  def *(that: Double): DrmLike[K] = OpAewUnaryFunc[K](A = this, f = _ * that)
-
-  def *:(that: Double): DrmLike[K] = OpAewUnaryFunc[K](A = this, f = that * _)
-
-  def ^(that: Double): DrmLike[K] = that match {
-    // Special handling of x ^2 and x ^ 0.5: we want consistent handling of x ^ 2 and x * x since
-    // pow(x,2) function return results different from x * x; but much of the code uses this
-    // interchangeably. Not having this done will create things like NaN entries on main diagonal
-    // of a distance matrix.
-    case 2.0 ⇒ OpAewUnaryFunc[K](A = this, f = x ⇒ x * x)
-    case 0.5 ⇒ OpAewUnaryFunc[K](A = this, f = math.sqrt _)
-    case _ ⇒ OpAewUnaryFunc[K](A = this, f = math.pow(_, that))
-  }
-
-  def /(that: Double): DrmLike[K] = OpAewUnaryFunc[K](A = this, f = _ / that, evalZeros = that == 0.0)
-
-  def /:(that: Double): DrmLike[K] = OpAewUnaryFunc[K](A = this, f = that / _, evalZeros = true)
-
-  def :%*%[B](that: DrmLike[B]): DrmLike[K] = OpABAnyKey[B,K](A = this.drm, B=that)
-
-  def %*%[B](that: DrmLike[B]): DrmLike[K] = this :%*% that
-
-  def :%*%(that: Matrix): DrmLike[K] = OpTimesRightMatrix[K](A = this.drm, right = that)
-
-  def %*%(that: Matrix): DrmLike[K] = this :%*% that
-
-  def :%*%(that: Vector): DrmLike[K] = OpAx(A = this.drm, x = that)
-
-  def %*%(that: Vector): DrmLike[K] = :%*%(that)
-
-  def t: DrmLike[Int] = OpAtAnyKey(A = drm)
-
-  def cbind(that: DrmLike[K]): DrmLike[K] = OpCbind(A = this.drm, B = that)
-
-  def cbind(that: Double): DrmLike[K] = OpCbindScalar(A = this.drm, x = that, leftBind = false)
-
-  def rbind(that: DrmLike[K]): DrmLike[K] = OpRbind(A = this.drm, B = that)
-
-  /**
-   * `rowSums` method for non-int keyed matrices.
-   *
-   * Slight problem here is the limitation of in-memory representation of Colt's Matrix, which can
-   * only have String row labels. Therefore, internally we do ".toString()" call on each key object,
-   * and then put it into [[Matrix]] row label bindings, at which point they are coerced to be Strings.
-   *
-   * This is obviously a suboptimal behavior, so as TODO we have here future enhancements of `collect'.
-   *
-   * @return map of row keys into row sums, front-end collected.
-   */
-  def rowSumsMap(): Map[String, Double] = {
-
-    implicit val ktag = drm.keyClassTag
-
-    val m = drm.mapBlock(ncol = 1) { case (keys, block) =>
-      keys -> dense(block.rowSums).t
-    }.collect
-    m.getRowLabelBindings.map { case (key, idx) => key -> m(idx, 0)}
-  }
-}
-
-class RLikeDrmIntOps(drm: DrmLike[Int]) extends RLikeDrmOps[Int](drm) {
-
-  import org.apache.mahout.math._
-  import scalabindings._
-  import RLikeDrmOps._
-
-  override def t: DrmLike[Int] = OpAt(A = drm)
-
-  def %*%:[K: ClassTag](that: DrmLike[K]): DrmLike[K] = OpAB[K](A = that, B = this.drm)
-
-  def %*%:(that: Matrix): DrmLike[Int] = OpTimesLeftMatrix(left = that, A = this.drm)
-
-  /** Row sums. This is of course applicable to Int-keyed distributed matrices only. */
-  def rowSums(): Vector = {
-    drm.mapBlock(ncol = 1) { case (keys, block) =>
-      // Collect block-wise rowsums and output them as one-column matrix.
-      keys -> dense(block.rowSums).t
-    }
-      .collect(::, 0)
-  }
-
-  /** Counts the non-zeros elements in each row returning a vector of the counts */
-  def numNonZeroElementsPerRow(): Vector = {
-    drm.mapBlock(ncol = 1) { case (keys, block) =>
-      // Collect block-wise row non-zero counts and output them as a one-column matrix.
-      keys -> dense(block.numNonZeroElementsPerRow).t
-    }
-      .collect(::, 0)
-  }
-
-  /** Row means */
-  def rowMeans(): Vector = {
-    drm.mapBlock(ncol = 1) { case (keys, block) =>
-      // Collect block-wise row means and output them as one-column matrix.
-      keys -> dense(block.rowMeans).t
-    }
-      .collect(::, 0)
-  }
-
-  /** Return diagonal vector */
-  def diagv: Vector = {
-    require(drm.ncol == drm.nrow, "Must be square to extract diagonal")
-    drm.mapBlock(ncol = 1) { case (keys, block) =>
-      keys -> dense(for (r <- block.view) yield r(keys(r.index))).t
-    }
-      .collect(::, 0)
-  }
-
-}
-
-object RLikeDrmOps {
-
-  implicit def double2ScalarOps(x: Double) = new DrmDoubleScalarOps(x)
-
-  implicit def drmInt2RLikeOps(drm: DrmLike[Int]): RLikeDrmIntOps = new RLikeDrmIntOps(drm)
-
-  implicit def drm2RLikeOps[K](drm: DrmLike[K]): RLikeDrmOps[K] = new RLikeDrmOps[K](drm)
-
-  implicit def rlikeOps2Drm[K](ops: RLikeDrmOps[K]): DrmLike[K] = ops.drm
-
-  implicit def ops2Drm[K](ops: DrmLikeOps[K]): DrmLike[K] = ops.drm
-
-  implicit def drm2cpops[K](drm: DrmLike[K]): CheckpointedOps[K] = new CheckpointedOps(drm)
-}