text: #
  # 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 for Chi-square hypothesis testing.
  Run with:
    bin/spark-submit examples/src/main/python/ml/chi_square_test_example.py
  """
  from __future__ import print_function
  
  from pyspark.sql import SparkSession
  # $example on$
  from pyspark.ml.linalg import Vectors
  from pyspark.ml.stat import ChiSquareTest
  # $example off$
  
  if __name__ == "__main__":
      spark = SparkSession \
          .builder \
          .appName("ChiSquareTestExample") \
          .getOrCreate()
  
      # $example on$
      data = [(0.0, Vectors.dense(0.5, 10.0)),
              (0.0, Vectors.dense(1.5, 20.0)),
              (1.0, Vectors.dense(1.5, 30.0)),
              (0.0, Vectors.dense(3.5, 30.0)),
              (0.0, Vectors.dense(3.5, 40.0)),
              (1.0, Vectors.dense(3.5, 40.0))]
      df = spark.createDataFrame(data, ["label", "features"])
  
      r = ChiSquareTest.test(df, "features", "label").head()
      print("pValues: " + str(r.pValues))
      print("degreesOfFreedom: " + str(r.degreesOfFreedom))
      print("statistics: " + str(r.statistics))
      # $example off$
  
      spark.stop()
  