Source code for pyspark.ml.evaluation

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from abc import abstractmethod, ABCMeta

from pyspark import since, keyword_only
from pyspark.ml.wrapper import JavaParams
from pyspark.ml.param import Param, Params, TypeConverters
from pyspark.ml.param.shared import HasLabelCol, HasPredictionCol, HasRawPredictionCol
from pyspark.ml.common import inherit_doc

__all__ = ['Evaluator', 'BinaryClassificationEvaluator', 'RegressionEvaluator',
           'MulticlassClassificationEvaluator']


@inherit_doc
[docs]class Evaluator(Params): """ Base class for evaluators that compute metrics from predictions. .. versionadded:: 1.4.0 """ __metaclass__ = ABCMeta @abstractmethod def _evaluate(self, dataset): """ Evaluates the output. :param dataset: a dataset that contains labels/observations and predictions :return: metric """ raise NotImplementedError() @since("1.4.0")
[docs] def evaluate(self, dataset, params=None): """ Evaluates the output with optional parameters. :param dataset: a dataset that contains labels/observations and predictions :param params: an optional param map that overrides embedded params :return: metric """ if params is None: params = dict() if isinstance(params, dict): if params: return self.copy(params)._evaluate(dataset) else: return self._evaluate(dataset) else: raise ValueError("Params must be a param map but got %s." % type(params))
@since("1.5.0")
[docs] def isLargerBetter(self): """ Indicates whether the metric returned by :py:meth:`evaluate` should be maximized (True, default) or minimized (False). A given evaluator may support multiple metrics which may be maximized or minimized. """ return True
@inherit_doc class JavaEvaluator(JavaParams, Evaluator): """ Base class for :py:class:`Evaluator`s that wrap Java/Scala implementations. """ __metaclass__ = ABCMeta def _evaluate(self, dataset): """ Evaluates the output. :param dataset: a dataset that contains labels/observations and predictions. :return: evaluation metric """ self._transfer_params_to_java() return self._java_obj.evaluate(dataset._jdf) def isLargerBetter(self): self._transfer_params_to_java() return self._java_obj.isLargerBetter() @inherit_doc
[docs]class BinaryClassificationEvaluator(JavaEvaluator, HasLabelCol, HasRawPredictionCol): """ .. note:: Experimental Evaluator for binary classification, which expects two input columns: rawPrediction and label. The rawPrediction column can be of type double (binary 0/1 prediction, or probability of label 1) or of type vector (length-2 vector of raw predictions, scores, or label probabilities). >>> from pyspark.ml.linalg import Vectors >>> scoreAndLabels = map(lambda x: (Vectors.dense([1.0 - x[0], x[0]]), x[1]), ... [(0.1, 0.0), (0.1, 1.0), (0.4, 0.0), (0.6, 0.0), (0.6, 1.0), (0.6, 1.0), (0.8, 1.0)]) >>> dataset = spark.createDataFrame(scoreAndLabels, ["raw", "label"]) ... >>> evaluator = BinaryClassificationEvaluator(rawPredictionCol="raw") >>> evaluator.evaluate(dataset) 0.70... >>> evaluator.evaluate(dataset, {evaluator.metricName: "areaUnderPR"}) 0.83... .. versionadded:: 1.4.0 """ metricName = Param(Params._dummy(), "metricName", "metric name in evaluation (areaUnderROC|areaUnderPR)", typeConverter=TypeConverters.toString) @keyword_only def __init__(self, rawPredictionCol="rawPrediction", labelCol="label", metricName="areaUnderROC"): """ __init__(self, rawPredictionCol="rawPrediction", labelCol="label", \ metricName="areaUnderROC") """ super(BinaryClassificationEvaluator, self).__init__() self._java_obj = self._new_java_obj( "org.apache.spark.ml.evaluation.BinaryClassificationEvaluator", self.uid) self._setDefault(rawPredictionCol="rawPrediction", labelCol="label", metricName="areaUnderROC") kwargs = self.__init__._input_kwargs self._set(**kwargs) @since("1.4.0")
[docs] def setMetricName(self, value): """ Sets the value of :py:attr:`metricName`. """ return self._set(metricName=value)
@since("1.4.0")
[docs] def getMetricName(self): """ Gets the value of metricName or its default value. """ return self.getOrDefault(self.metricName)
@keyword_only @since("1.4.0")
[docs] def setParams(self, rawPredictionCol="rawPrediction", labelCol="label", metricName="areaUnderROC"): """ setParams(self, rawPredictionCol="rawPrediction", labelCol="label", \ metricName="areaUnderROC") Sets params for binary classification evaluator. """ kwargs = self.setParams._input_kwargs return self._set(**kwargs)
@inherit_doc
[docs]class RegressionEvaluator(JavaEvaluator, HasLabelCol, HasPredictionCol): """ .. note:: Experimental Evaluator for Regression, which expects two input columns: prediction and label. >>> scoreAndLabels = [(-28.98343821, -27.0), (20.21491975, 21.5), ... (-25.98418959, -22.0), (30.69731842, 33.0), (74.69283752, 71.0)] >>> dataset = spark.createDataFrame(scoreAndLabels, ["raw", "label"]) ... >>> evaluator = RegressionEvaluator(predictionCol="raw") >>> evaluator.evaluate(dataset) 2.842... >>> evaluator.evaluate(dataset, {evaluator.metricName: "r2"}) 0.993... >>> evaluator.evaluate(dataset, {evaluator.metricName: "mae"}) 2.649... .. versionadded:: 1.4.0 """ metricName = Param(Params._dummy(), "metricName", """metric name in evaluation - one of: rmse - root mean squared error (default) mse - mean squared error r2 - r^2 metric mae - mean absolute error.""", typeConverter=TypeConverters.toString) @keyword_only def __init__(self, predictionCol="prediction", labelCol="label", metricName="rmse"): """ __init__(self, predictionCol="prediction", labelCol="label", \ metricName="rmse") """ super(RegressionEvaluator, self).__init__() self._java_obj = self._new_java_obj( "org.apache.spark.ml.evaluation.RegressionEvaluator", self.uid) self._setDefault(predictionCol="prediction", labelCol="label", metricName="rmse") kwargs = self.__init__._input_kwargs self._set(**kwargs) @since("1.4.0")
[docs] def setMetricName(self, value): """ Sets the value of :py:attr:`metricName`. """ return self._set(metricName=value)
@since("1.4.0")
[docs] def getMetricName(self): """ Gets the value of metricName or its default value. """ return self.getOrDefault(self.metricName)
@keyword_only @since("1.4.0")
[docs] def setParams(self, predictionCol="prediction", labelCol="label", metricName="rmse"): """ setParams(self, predictionCol="prediction", labelCol="label", \ metricName="rmse") Sets params for regression evaluator. """ kwargs = self.setParams._input_kwargs return self._set(**kwargs)
@inherit_doc
[docs]class MulticlassClassificationEvaluator(JavaEvaluator, HasLabelCol, HasPredictionCol): """ .. note:: Experimental Evaluator for Multiclass Classification, which expects two input columns: prediction and label. >>> scoreAndLabels = [(0.0, 0.0), (0.0, 1.0), (0.0, 0.0), ... (1.0, 0.0), (1.0, 1.0), (1.0, 1.0), (1.0, 1.0), (2.0, 2.0), (2.0, 0.0)] >>> dataset = spark.createDataFrame(scoreAndLabels, ["prediction", "label"]) ... >>> evaluator = MulticlassClassificationEvaluator(predictionCol="prediction") >>> evaluator.evaluate(dataset) 0.66... >>> evaluator.evaluate(dataset, {evaluator.metricName: "accuracy"}) 0.66... .. versionadded:: 1.5.0 """ metricName = Param(Params._dummy(), "metricName", "metric name in evaluation " "(f1|weightedPrecision|weightedRecall|accuracy)", typeConverter=TypeConverters.toString) @keyword_only def __init__(self, predictionCol="prediction", labelCol="label", metricName="f1"): """ __init__(self, predictionCol="prediction", labelCol="label", \ metricName="f1") """ super(MulticlassClassificationEvaluator, self).__init__() self._java_obj = self._new_java_obj( "org.apache.spark.ml.evaluation.MulticlassClassificationEvaluator", self.uid) self._setDefault(predictionCol="prediction", labelCol="label", metricName="f1") kwargs = self.__init__._input_kwargs self._set(**kwargs) @since("1.5.0")
[docs] def setMetricName(self, value): """ Sets the value of :py:attr:`metricName`. """ return self._set(metricName=value)
@since("1.5.0")
[docs] def getMetricName(self): """ Gets the value of metricName or its default value. """ return self.getOrDefault(self.metricName)
@keyword_only @since("1.5.0")
[docs] def setParams(self, predictionCol="prediction", labelCol="label", metricName="f1"): """ setParams(self, predictionCol="prediction", labelCol="label", \ metricName="f1") Sets params for multiclass classification evaluator. """ kwargs = self.setParams._input_kwargs return self._set(**kwargs)
if __name__ == "__main__": import doctest from pyspark.sql import SparkSession globs = globals().copy() # The small batch size here ensures that we see multiple batches, # even in these small test examples: spark = SparkSession.builder\ .master("local[2]")\ .appName("ml.evaluation tests")\ .getOrCreate() sc = spark.sparkContext globs['sc'] = sc globs['spark'] = spark (failure_count, test_count) = doctest.testmod( globs=globs, optionflags=doctest.ELLIPSIS) spark.stop() if failure_count: exit(-1)