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Diffstat (limited to 'examples/src/main/python/mllib/multi_class_metrics_example.py')
-rw-r--r-- | examples/src/main/python/mllib/multi_class_metrics_example.py | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/examples/src/main/python/mllib/multi_class_metrics_example.py b/examples/src/main/python/mllib/multi_class_metrics_example.py new file mode 100644 index 0000000000..cd56b3c97c --- /dev/null +++ b/examples/src/main/python/mllib/multi_class_metrics_example.py @@ -0,0 +1,69 @@ +# +# Licensed to the Apache Software Foundation (ASF) under one or more +# contributor license agreements. See the NOTICE file distributed with +# this work for additional information regarding copyright ownership. +# The ASF licenses this file to You under the Apache License, Version 2.0 +# (the "License"); you may not use this file except in compliance with +# the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# + +# $example on$ +from pyspark.mllib.classification import LogisticRegressionWithLBFGS +from pyspark.mllib.util import MLUtils +from pyspark.mllib.evaluation import MulticlassMetrics +# $example off$ + +from pyspark import SparkContext + +if __name__ == "__main__": + sc = SparkContext(appName="MultiClassMetricsExample") + + # Several of the methods available in scala are currently missing from pyspark + # $example on$ + # Load training data in LIBSVM format + data = MLUtils.loadLibSVMFile(sc, "data/mllib/sample_multiclass_classification_data.txt") + + # Split data into training (60%) and test (40%) + training, test = data.randomSplit([0.6, 0.4], seed=11L) + training.cache() + + # Run training algorithm to build the model + model = LogisticRegressionWithLBFGS.train(training, numClasses=3) + + # Compute raw scores on the test set + predictionAndLabels = test.map(lambda lp: (float(model.predict(lp.features)), lp.label)) + + # Instantiate metrics object + metrics = MulticlassMetrics(predictionAndLabels) + + # Overall statistics + precision = metrics.precision() + recall = metrics.recall() + f1Score = metrics.fMeasure() + print("Summary Stats") + print("Precision = %s" % precision) + print("Recall = %s" % recall) + print("F1 Score = %s" % f1Score) + + # Statistics by class + labels = data.map(lambda lp: lp.label).distinct().collect() + for label in sorted(labels): + print("Class %s precision = %s" % (label, metrics.precision(label))) + print("Class %s recall = %s" % (label, metrics.recall(label))) + print("Class %s F1 Measure = %s" % (label, metrics.fMeasure(label, beta=1.0))) + + # Weighted stats + print("Weighted recall = %s" % metrics.weightedRecall) + print("Weighted precision = %s" % metrics.weightedPrecision) + print("Weighted F(1) Score = %s" % metrics.weightedFMeasure()) + print("Weighted F(0.5) Score = %s" % metrics.weightedFMeasure(beta=0.5)) + print("Weighted false positive rate = %s" % metrics.weightedFalsePositiveRate) + # $example off$ |