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Diffstat (limited to 'examples/src/main/python/mllib/regression_metrics_example.py')
-rw-r--r-- | examples/src/main/python/mllib/regression_metrics_example.py | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/examples/src/main/python/mllib/regression_metrics_example.py b/examples/src/main/python/mllib/regression_metrics_example.py new file mode 100644 index 0000000000..a3a83aafd7 --- /dev/null +++ b/examples/src/main/python/mllib/regression_metrics_example.py @@ -0,0 +1,59 @@ +# +# 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.regression import LabeledPoint, LinearRegressionWithSGD +from pyspark.mllib.evaluation import RegressionMetrics +from pyspark.mllib.linalg import DenseVector +# $example off$ + +from pyspark import SparkContext + +if __name__ == "__main__": + sc = SparkContext(appName="Regression Metrics Example") + + # $example on$ + # Load and parse the data + def parsePoint(line): + values = line.split() + return LabeledPoint(float(values[0]), + DenseVector([float(x.split(':')[1]) for x in values[1:]])) + + data = sc.textFile("data/mllib/sample_linear_regression_data.txt") + parsedData = data.map(parsePoint) + + # Build the model + model = LinearRegressionWithSGD.train(parsedData) + + # Get predictions + valuesAndPreds = parsedData.map(lambda p: (float(model.predict(p.features)), p.label)) + + # Instantiate metrics object + metrics = RegressionMetrics(valuesAndPreds) + + # Squared Error + print("MSE = %s" % metrics.meanSquaredError) + print("RMSE = %s" % metrics.rootMeanSquaredError) + + # R-squared + print("R-squared = %s" % metrics.r2) + + # Mean absolute error + print("MAE = %s" % metrics.meanAbsoluteError) + + # Explained variance + print("Explained variance = %s" % metrics.explainedVariance) + # $example off$ |