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
from pyspark.ml.util import JavaMLReadable, JavaMLWritable
__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,
JavaMLReadable, JavaMLWritable):
"""
.. 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...
>>> bce_path = temp_path + "/bce"
>>> evaluator.save(bce_path)
>>> evaluator2 = BinaryClassificationEvaluator.load(bce_path)
>>> str(evaluator2.getRawPredictionCol())
'raw'
.. 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._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._input_kwargs
return self._set(**kwargs)
@inherit_doc
[docs]class RegressionEvaluator(JavaEvaluator, HasLabelCol, HasPredictionCol,
JavaMLReadable, JavaMLWritable):
"""
.. 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...
>>> re_path = temp_path + "/re"
>>> evaluator.save(re_path)
>>> evaluator2 = RegressionEvaluator.load(re_path)
>>> str(evaluator2.getPredictionCol())
'raw'
.. 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._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._input_kwargs
return self._set(**kwargs)
@inherit_doc
[docs]class MulticlassClassificationEvaluator(JavaEvaluator, HasLabelCol, HasPredictionCol,
JavaMLReadable, JavaMLWritable):
"""
.. 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...
>>> mce_path = temp_path + "/mce"
>>> evaluator.save(mce_path)
>>> evaluator2 = MulticlassClassificationEvaluator.load(mce_path)
>>> str(evaluator2.getPredictionCol())
'prediction'
.. 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._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._input_kwargs
return self._set(**kwargs)
if __name__ == "__main__":
import doctest
import tempfile
import pyspark.ml.evaluation
from pyspark.sql import SparkSession
globs = pyspark.ml.evaluation.__dict__.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()
globs['spark'] = spark
temp_path = tempfile.mkdtemp()
globs['temp_path'] = temp_path
try:
(failure_count, test_count) = doctest.testmod(globs=globs, optionflags=doctest.ELLIPSIS)
spark.stop()
finally:
from shutil import rmtree
try:
rmtree(temp_path)
except OSError:
pass
if failure_count:
exit(-1)
