From 3f7de7db4cf7c5e2824cb91087c5e9d4beb0f738 Mon Sep 17 00:00:00 2001 From: George Dittmar Date: Mon, 20 Jul 2015 08:55:37 -0700 Subject: [PATCH] [SPARK-7422] [MLLIB] Add argmax to Vector, SparseVector Modifying Vector, DenseVector, and SparseVector to implement argmax functionality. This work is to set the stage for changes to be done in Spark-7423. Author: George Dittmar Author: George Author: dittmarg Author: Xiangrui Meng Closes #6112 from GeorgeDittmar/SPARK-7422 and squashes the following commits: 3e0a939 [George Dittmar] Merge pull request #1 from mengxr/SPARK-7422 127dec5 [Xiangrui Meng] update argmax impl 2ea6a55 [George Dittmar] Added MimaExcludes for Vectors.argmax 98058f4 [George Dittmar] Merge branch 'master' of github.com:apache/spark into SPARK-7422 5fd9380 [George Dittmar] fixing style check error 42341fb [George Dittmar] refactoring arg max check to better handle zero values b22af46 [George Dittmar] Fixing spaces between commas in unit test f2eba2f [George Dittmar] Cleaning up unit tests to be fewer lines aa330e3 [George Dittmar] Fixing some last if else spacing issues ac53c55 [George Dittmar] changing dense vector argmax unit test to be one line call vs 2 d5b5423 [George Dittmar] Fixing code style and updating if logic on when to check for zero values ee1a85a [George Dittmar] Cleaning up unit tests a bit and modifying a few cases 3ee8711 [George Dittmar] Fixing corner case issue with zeros in the active values of the sparse vector. Updated unit tests b1f059f [George Dittmar] Added comment before we start arg max calculation. Updated unit tests to cover corner cases f21dcce [George Dittmar] commit af17981 [dittmarg] Initial work fixing bug that was made clear in pr eeda560 [George] Fixing SparseVector argmax function to ignore zero values while doing the calculation. 4526acc [George] Merge branch 'master' of github.com:apache/spark into SPARK-7422 df9538a [George] Added argmax to sparse vector and added unit test 3cffed4 [George] Adding unit tests for argmax functions for Dense and Sparse vectors 04677af [George] initial work on adding argmax to Vector and SparseVector --- .../apache/spark/mllib/linalg/Vectors.scala | 57 +++++++++++++++++-- .../spark/mllib/linalg/VectorsSuite.scala | 39 +++++++++++++ project/MimaExcludes.scala | 4 ++ 3 files changed, 95 insertions(+), 5 deletions(-) diff --git a/mllib/src/main/scala/org/apache/spark/mllib/linalg/Vectors.scala b/mllib/src/main/scala/org/apache/spark/mllib/linalg/Vectors.scala index e048b01d92462..9067b3ba9a7bb 100644 --- a/mllib/src/main/scala/org/apache/spark/mllib/linalg/Vectors.scala +++ b/mllib/src/main/scala/org/apache/spark/mllib/linalg/Vectors.scala @@ -150,6 +150,12 @@ sealed trait Vector extends Serializable { toDense } } + + /** + * Find the index of a maximal element. Returns the first maximal element in case of a tie. + * Returns -1 if vector has length 0. + */ + def argmax: Int } /** @@ -588,11 +594,7 @@ class DenseVector(val values: Array[Double]) extends Vector { new SparseVector(size, ii, vv) } - /** - * Find the index of a maximal element. Returns the first maximal element in case of a tie. - * Returns -1 if vector has length 0. - */ - private[spark] def argmax: Int = { + override def argmax: Int = { if (size == 0) { -1 } else { @@ -717,6 +719,51 @@ class SparseVector( new SparseVector(size, ii, vv) } } + + override def argmax: Int = { + if (size == 0) { + -1 + } else { + // Find the max active entry. + var maxIdx = indices(0) + var maxValue = values(0) + var maxJ = 0 + var j = 1 + val na = numActives + while (j < na) { + val v = values(j) + if (v > maxValue) { + maxValue = v + maxIdx = indices(j) + maxJ = j + } + j += 1 + } + + // If the max active entry is nonpositive and there exists inactive ones, find the first zero. + if (maxValue <= 0.0 && na < size) { + if (maxValue == 0.0) { + // If there exists an inactive entry before maxIdx, find it and return its index. + if (maxJ < maxIdx) { + var k = 0 + while (k < maxJ && indices(k) == k) { + k += 1 + } + maxIdx = k + } + } else { + // If the max active value is negative, find and return the first inactive index. + var k = 0 + while (k < na && indices(k) == k) { + k += 1 + } + maxIdx = k + } + } + + maxIdx + } + } } object SparseVector { diff --git a/mllib/src/test/scala/org/apache/spark/mllib/linalg/VectorsSuite.scala b/mllib/src/test/scala/org/apache/spark/mllib/linalg/VectorsSuite.scala index 178d95a7b94ec..03be4119bdaca 100644 --- a/mllib/src/test/scala/org/apache/spark/mllib/linalg/VectorsSuite.scala +++ b/mllib/src/test/scala/org/apache/spark/mllib/linalg/VectorsSuite.scala @@ -62,11 +62,50 @@ class VectorsSuite extends SparkFunSuite with Logging { assert(vec.toArray.eq(arr)) } + test("dense argmax") { + val vec = Vectors.dense(Array.empty[Double]).asInstanceOf[DenseVector] + assert(vec.argmax === -1) + + val vec2 = Vectors.dense(arr).asInstanceOf[DenseVector] + assert(vec2.argmax === 3) + + val vec3 = Vectors.dense(Array(-1.0, 0.0, -2.0, 1.0)).asInstanceOf[DenseVector] + assert(vec3.argmax === 3) + } + test("sparse to array") { val vec = Vectors.sparse(n, indices, values).asInstanceOf[SparseVector] assert(vec.toArray === arr) } + test("sparse argmax") { + val vec = Vectors.sparse(0, Array.empty[Int], Array.empty[Double]).asInstanceOf[SparseVector] + assert(vec.argmax === -1) + + val vec2 = Vectors.sparse(n, indices, values).asInstanceOf[SparseVector] + assert(vec2.argmax === 3) + + val vec3 = Vectors.sparse(5, Array(2, 3, 4), Array(1.0, 0.0, -.7)) + assert(vec3.argmax === 2) + + // check for case that sparse vector is created with + // only negative values {0.0, 0.0,-1.0, -0.7, 0.0} + val vec4 = Vectors.sparse(5, Array(2, 3), Array(-1.0, -.7)) + assert(vec4.argmax === 0) + + val vec5 = Vectors.sparse(11, Array(0, 3, 10), Array(-1.0, -.7, 0.0)) + assert(vec5.argmax === 1) + + val vec6 = Vectors.sparse(11, Array(0, 1, 2), Array(-1.0, -.7, 0.0)) + assert(vec6.argmax === 2) + + val vec7 = Vectors.sparse(5, Array(0, 1, 3), Array(-1.0, 0.0, -.7)) + assert(vec7.argmax === 1) + + val vec8 = Vectors.sparse(5, Array(1, 2), Array(0.0, -1.0)) + assert(vec8.argmax === 0) + } + test("vector equals") { val dv1 = Vectors.dense(arr.clone()) val dv2 = Vectors.dense(arr.clone()) diff --git a/project/MimaExcludes.scala b/project/MimaExcludes.scala index 36417f5df9f2d..dd852547492aa 100644 --- a/project/MimaExcludes.scala +++ b/project/MimaExcludes.scala @@ -98,6 +98,10 @@ object MimaExcludes { "org.apache.spark.api.r.StringRRDD.this"), ProblemFilters.exclude[MissingMethodProblem]( "org.apache.spark.api.r.BaseRRDD.this") + ) ++ Seq( + // SPARK-7422 add argmax for sparse vectors + ProblemFilters.exclude[MissingMethodProblem]( + "org.apache.spark.mllib.linalg.Vector.argmax") ) case v if v.startsWith("1.4") =>