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+#
+# 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.
+#
+
+"""
+An example of how to use DataFrame for ML. Run with::
+ bin/spark-submit examples/src/main/python/ml/dataframe_example.py <input>
+"""
+from __future__ import print_function
+
+import os
+import sys
+import tempfile
+import shutil
+
+from pyspark import SparkContext
+from pyspark.sql import SQLContext
+from pyspark.mllib.stat import Statistics
+
+if __name__ == "__main__":
+ if len(sys.argv) > 2:
+ print("Usage: dataframe_example.py <libsvm file>", file=sys.stderr)
+ exit(-1)
+ sc = SparkContext(appName="DataFrameExample")
+ sqlContext = SQLContext(sc)
+ if len(sys.argv) == 2:
+ input = sys.argv[1]
+ else:
+ input = "data/mllib/sample_libsvm_data.txt"
+
+ # Load input data
+ print("Loading LIBSVM file with UDT from " + input + ".")
+ df = sqlContext.read.format("libsvm").load(input).cache()
+ print("Schema from LIBSVM:")
+ df.printSchema()
+ print("Loaded training data as a DataFrame with " +
+ str(df.count()) + " records.")
+
+ # Show statistical summary of labels.
+ labelSummary = df.describe("label")
+ labelSummary.show()
+
+ # Convert features column to an RDD of vectors.
+ features = df.select("features").map(lambda r: r.features)
+ summary = Statistics.colStats(features)
+ print("Selected features column with average values:\n" +
+ str(summary.mean()))
+
+ # Save the records in a parquet file.
+ tempdir = tempfile.NamedTemporaryFile(delete=False).name
+ os.unlink(tempdir)
+ print("Saving to " + tempdir + " as Parquet file.")
+ df.write.parquet(tempdir)
+
+ # Load the records back.
+ print("Loading Parquet file with UDT from " + tempdir)
+ newDF = sqlContext.read.parquet(tempdir)
+ print("Schema from Parquet:")
+ newDF.printSchema()
+ shutil.rmtree(tempdir)
+
+ sc.stop()