[SPARK-6094] [MLLIB] Add MultilabelMetrics in PySpark/MLlib

Add MultilabelMetrics in PySpark/MLlib

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #6276 from yanboliang/spark-6094 and squashes the following commits:

b8e3343 [Yanbo Liang] Add MultilabelMetrics in PySpark/MLlib

mllib/src/main/scala/org/apache/spark/mllib/evaluation/MultilabelMetrics.scala

@@ -19,6 +19,7 @@ package org.apache.spark.mllib.evaluation
 
 import org.apache.spark.rdd.RDD
 import org.apache.spark.SparkContext._
+import org.apache.spark.sql.DataFrame
 
 /**
  * Evaluator for multilabel classification.
@@ -27,6 +28,13 @@ import org.apache.spark.SparkContext._
  */
 class MultilabelMetrics(predictionAndLabels: RDD[(Array[Double], Array[Double])]) {
 
+  /**
+   * An auxiliary constructor taking a DataFrame.
+   * @param predictionAndLabels a DataFrame with two double array columns: prediction and label
+   */
+  private[mllib] def this(predictionAndLabels: DataFrame) =
+    this(predictionAndLabels.map(r => (r.getSeq[Double](0).toArray, r.getSeq[Double](1).toArray)))
+
   private lazy val numDocs: Long = predictionAndLabels.count()
 
   private lazy val numLabels: Long = predictionAndLabels.flatMap { case (_, labels) =>

python/pyspark/mllib/evaluation.py

@@ -343,6 +343,123 @@ class RankingMetrics(JavaModelWrapper):
         return self.call("ndcgAt", int(k))
 
 
+class MultilabelMetrics(JavaModelWrapper):
+    """
+    Evaluator for multilabel classification.
+
+    >>> predictionAndLabels = sc.parallelize([([0.0, 1.0], [0.0, 2.0]), ([0.0, 2.0], [0.0, 1.0]),
+    ...     ([], [0.0]), ([2.0], [2.0]), ([2.0, 0.0], [2.0, 0.0]),
+    ...     ([0.0, 1.0, 2.0], [0.0, 1.0]), ([1.0], [1.0, 2.0])])
+    >>> metrics = MultilabelMetrics(predictionAndLabels)
+    >>> metrics.precision(0.0)
+    1.0
+    >>> metrics.recall(1.0)
+    0.66...
+    >>> metrics.f1Measure(2.0)
+    0.5
+    >>> metrics.precision()
+    0.66...
+    >>> metrics.recall()
+    0.64...
+    >>> metrics.f1Measure()
+    0.63...
+    >>> metrics.microPrecision
+    0.72...
+    >>> metrics.microRecall
+    0.66...
+    >>> metrics.microF1Measure
+    0.69...
+    >>> metrics.hammingLoss
+    0.33...
+    >>> metrics.subsetAccuracy
+    0.28...
+    >>> metrics.accuracy
+    0.54...
+    """
+
+    def __init__(self, predictionAndLabels):
+        sc = predictionAndLabels.ctx
+        sql_ctx = SQLContext(sc)
+        df = sql_ctx.createDataFrame(predictionAndLabels,
+                                     schema=sql_ctx._inferSchema(predictionAndLabels))
+        java_class = sc._jvm.org.apache.spark.mllib.evaluation.MultilabelMetrics
+        java_model = java_class(df._jdf)
+        super(MultilabelMetrics, self).__init__(java_model)
+
+    def precision(self, label=None):
+        """
+        Returns precision or precision for a given label (category) if specified.
+        """
+        if label is None:
+            return self.call("precision")
+        else:
+            return self.call("precision", float(label))
+
+    def recall(self, label=None):
+        """
+        Returns recall or recall for a given label (category) if specified.
+        """
+        if label is None:
+            return self.call("recall")
+        else:
+            return self.call("recall", float(label))
+
+    def f1Measure(self, label=None):
+        """
+        Returns f1Measure or f1Measure for a given label (category) if specified.
+        """
+        if label is None:
+            return self.call("f1Measure")
+        else:
+            return self.call("f1Measure", float(label))
+
+    @property
+    def microPrecision(self):
+        """
+        Returns micro-averaged label-based precision.
+        (equals to micro-averaged document-based precision)
+        """
+        return self.call("microPrecision")
+
+    @property
+    def microRecall(self):
+        """
+        Returns micro-averaged label-based recall.
+        (equals to micro-averaged document-based recall)
+        """
+        return self.call("microRecall")
+
+    @property
+    def microF1Measure(self):
+        """
+        Returns micro-averaged label-based f1-measure.
+        (equals to micro-averaged document-based f1-measure)
+        """
+        return self.call("microF1Measure")
+
+    @property
+    def hammingLoss(self):
+        """
+        Returns Hamming-loss.
+        """
+        return self.call("hammingLoss")
+
+    @property
+    def subsetAccuracy(self):
+        """
+        Returns subset accuracy.
+        (for equal sets of labels)
+        """
+        return self.call("subsetAccuracy")
+
+    @property
+    def accuracy(self):
+        """
+        Returns accuracy.
+        """
+        return self.call("accuracy")
+
+
 def _test():
     import doctest
     from pyspark import SparkContext