spark/python/examples/pi.py

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1.3 KiB
Python
Executable File

#
# 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.
#
import sys
from random import random
from operator import add
from pyspark import SparkContext
if __name__ == "__main__":
if len(sys.argv) == 1:
print >> sys.stderr, "Usage: pi <master> [<slices>]"
exit(-1)
sc = SparkContext(sys.argv[1], "PythonPi")
slices = int(sys.argv[2]) if len(sys.argv) > 2 else 2
n = 100000 * slices
def f(_):
x = random() * 2 - 1
y = random() * 2 - 1
return 1 if x ** 2 + y ** 2 < 1 else 0
count = sc.parallelize(xrange(1, n+1), slices).map(f).reduce(add)
print "Pi is roughly %f" % (4.0 * count / n)