RankingEvaluator¶
-
class
pyspark.ml.evaluation.
RankingEvaluator
(predictionCol='prediction', labelCol='label', metricName='meanAveragePrecision', k=10)[source]¶ Note
Experimental
Evaluator for Ranking, which expects two input columns: prediction and label.
>>> scoreAndLabels = [([1.0, 6.0, 2.0, 7.0, 8.0, 3.0, 9.0, 10.0, 4.0, 5.0], ... [1.0, 2.0, 3.0, 4.0, 5.0]), ... ([4.0, 1.0, 5.0, 6.0, 2.0, 7.0, 3.0, 8.0, 9.0, 10.0], [1.0, 2.0, 3.0]), ... ([1.0, 2.0, 3.0, 4.0, 5.0], [])] >>> dataset = spark.createDataFrame(scoreAndLabels, ["prediction", "label"]) ... >>> evaluator = RankingEvaluator() >>> evaluator.setPredictionCol("prediction") RankingEvaluator... >>> evaluator.evaluate(dataset) 0.35... >>> evaluator.evaluate(dataset, {evaluator.metricName: "precisionAtK", evaluator.k: 2}) 0.33... >>> ranke_path = temp_path + "/ranke" >>> evaluator.save(ranke_path) >>> evaluator2 = RankingEvaluator.load(ranke_path) >>> str(evaluator2.getPredictionCol()) 'prediction'
New in version 3.0.0.
Methods
Attributes
Methods Documentation
-
clear
(param)¶ Clears a param from the param map if it has been explicitly set.
-
copy
(extra=None)¶ Creates a copy of this instance with the same uid and some extra params. This implementation first calls Params.copy and then make a copy of the companion Java pipeline component with extra params. So both the Python wrapper and the Java pipeline component get copied.
- Parameters
extra – Extra parameters to copy to the new instance
- Returns
Copy of this instance
-
evaluate
(dataset, params=None)¶ Evaluates the output with optional parameters.
- Parameters
dataset – a dataset that contains labels/observations and predictions
params – an optional param map that overrides embedded params
- Returns
metric
New in version 1.4.0.
-
explainParam
(param)¶ Explains a single param and returns its name, doc, and optional default value and user-supplied value in a string.
-
explainParams
()¶ Returns the documentation of all params with their optionally default values and user-supplied values.
-
extractParamMap
(extra=None)¶ Extracts the embedded default param values and user-supplied values, and then merges them with extra values from input into a flat param map, where the latter value is used if there exist conflicts, i.e., with ordering: default param values < user-supplied values < extra.
- Parameters
extra – extra param values
- Returns
merged param map
-
getLabelCol
()¶ Gets the value of labelCol or its default value.
-
getOrDefault
(param)¶ Gets the value of a param in the user-supplied param map or its default value. Raises an error if neither is set.
-
getParam
(paramName)¶ Gets a param by its name.
-
getPredictionCol
()¶ Gets the value of predictionCol or its default value.
-
hasDefault
(param)¶ Checks whether a param has a default value.
-
hasParam
(paramName)¶ Tests whether this instance contains a param with a given (string) name.
-
isDefined
(param)¶ Checks whether a param is explicitly set by user or has a default value.
-
isLargerBetter
()¶ Indicates whether the metric returned by
evaluate()
should be maximized (True, default) or minimized (False). A given evaluator may support multiple metrics which may be maximized or minimized.New in version 1.5.0.
-
isSet
(param)¶ Checks whether a param is explicitly set by user.
-
classmethod
load
(path)¶ Reads an ML instance from the input path, a shortcut of read().load(path).
-
classmethod
read
()¶ Returns an MLReader instance for this class.
-
save
(path)¶ Save this ML instance to the given path, a shortcut of ‘write().save(path)’.
-
set
(param, value)¶ Sets a parameter in the embedded param map.
-
setMetricName
(value)[source]¶ Sets the value of
metricName
.New in version 3.0.0.
-
setParams
(self, predictionCol='prediction', labelCol='label', metricName='meanAveragePrecision', k=10)[source]¶ Sets params for ranking evaluator.
New in version 3.0.0.
-
setPredictionCol
(value)[source]¶ Sets the value of
predictionCol
.New in version 3.0.0.
-
write
()¶ Returns an MLWriter instance for this ML instance.
Attributes Documentation
-
k
= Param(parent='undefined', name='k', doc='The ranking position value used in meanAveragePrecisionAtK|precisionAtK|ndcgAtK|recallAtK. Must be > 0. The default value is 10.')¶
-
labelCol
= Param(parent='undefined', name='labelCol', doc='label column name.')¶
-
metricName
= Param(parent='undefined', name='metricName', doc='metric name in evaluation (meanAveragePrecision|meanAveragePrecisionAtK|precisionAtK|ndcgAtK|recallAtK)')¶
-
params
¶ Returns all params ordered by name. The default implementation uses
dir()
to get all attributes of typeParam
.
-
predictionCol
= Param(parent='undefined', name='predictionCol', doc='prediction column name.')¶
-