From 354f8f11bd4b20fa99bd67a98da3525fd3d75c81 Mon Sep 17 00:00:00 2001 From: "wm624@hotmail.com" Date: Sat, 14 May 2016 09:45:56 +0100 Subject: [SPARK-15096][ML] LogisticRegression MultiClassSummarizer numClasses can fail if no valid labels are found ## What changes were proposed in this pull request? (Please fill in changes proposed in this fix) Throw better exception when numClasses is empty and empty.max is thrown. ## How was this patch tested? (Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests) Add a new unit test, which calls histogram with empty numClasses. Author: wm624@hotmail.com Closes #12969 from wangmiao1981/logisticR. --- .../scala/org/apache/spark/ml/classification/LogisticRegression.scala | 2 +- .../org/apache/spark/ml/classification/LogisticRegressionSuite.scala | 4 ++++ 2 files changed, 5 insertions(+), 1 deletion(-) (limited to 'mllib') diff --git a/mllib/src/main/scala/org/apache/spark/ml/classification/LogisticRegression.scala b/mllib/src/main/scala/org/apache/spark/ml/classification/LogisticRegression.scala index 3e8040d3e9..ffd03e55b5 100644 --- a/mllib/src/main/scala/org/apache/spark/ml/classification/LogisticRegression.scala +++ b/mllib/src/main/scala/org/apache/spark/ml/classification/LogisticRegression.scala @@ -745,7 +745,7 @@ private[classification] class MultiClassSummarizer extends Serializable { def countInvalid: Long = totalInvalidCnt /** @return The number of distinct labels in the input dataset. */ - def numClasses: Int = distinctMap.keySet.max + 1 + def numClasses: Int = if (distinctMap.isEmpty) 0 else distinctMap.keySet.max + 1 /** @return The weightSum of each label in the input dataset. */ def histogram: Array[Double] = { diff --git a/mllib/src/test/scala/org/apache/spark/ml/classification/LogisticRegressionSuite.scala b/mllib/src/test/scala/org/apache/spark/ml/classification/LogisticRegressionSuite.scala index f127aa217c..69650ebb36 100644 --- a/mllib/src/test/scala/org/apache/spark/ml/classification/LogisticRegressionSuite.scala +++ b/mllib/src/test/scala/org/apache/spark/ml/classification/LogisticRegressionSuite.scala @@ -256,6 +256,10 @@ class LogisticRegressionSuite assert(summarizer4.countInvalid === 2) assert(summarizer4.numClasses === 4) + val summarizer5 = new MultiClassSummarizer + assert(summarizer5.histogram.isEmpty) + assert(summarizer5.numClasses === 0) + // small map merges large one val summarizerA = summarizer1.merge(summarizer2) assert(summarizerA.hashCode() === summarizer2.hashCode()) -- cgit v1.2.3