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author | Sandeep <sandeep@techaddict.me> | 2014-05-06 17:27:52 -0700 |
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committer | Matei Zaharia <matei@databricks.com> | 2014-05-06 17:27:52 -0700 |
commit | a000b5c3b0438c17e9973df4832c320210c29c27 (patch) | |
tree | 446bbe902ecd6de05072357f7ef25aaeb0687b73 /examples/src/main/python/kmeans.py | |
parent | 39b8b1489ff92697e4aeec997cdc436c7079d6f8 (diff) | |
download | spark-a000b5c3b0438c17e9973df4832c320210c29c27.tar.gz spark-a000b5c3b0438c17e9973df4832c320210c29c27.tar.bz2 spark-a000b5c3b0438c17e9973df4832c320210c29c27.zip |
SPARK-1637: Clean up examples for 1.0
- [x] Move all of them into subpackages of org.apache.spark.examples (right now some are in org.apache.spark.streaming.examples, for instance, and others are in org.apache.spark.examples.mllib)
- [x] Move Python examples into examples/src/main/python
- [x] Update docs to reflect these changes
Author: Sandeep <sandeep@techaddict.me>
This patch had conflicts when merged, resolved by
Committer: Matei Zaharia <matei@databricks.com>
Closes #571 from techaddict/SPARK-1637 and squashes the following commits:
47ef86c [Sandeep] Changes based on Discussions on PR, removing use of RawTextHelper from examples
8ed2d3f [Sandeep] Docs Updated for changes, Change for java examples
5f96121 [Sandeep] Move Python examples into examples/src/main/python
0a8dd77 [Sandeep] Move all Scala Examples to org.apache.spark.examples (some are in org.apache.spark.streaming.examples, for instance, and others are in org.apache.spark.examples.mllib)
Diffstat (limited to 'examples/src/main/python/kmeans.py')
-rwxr-xr-x | examples/src/main/python/kmeans.py | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/examples/src/main/python/kmeans.py b/examples/src/main/python/kmeans.py new file mode 100755 index 0000000000..e3596488fa --- /dev/null +++ b/examples/src/main/python/kmeans.py @@ -0,0 +1,73 @@ +# +# 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. +# + +""" +The K-means algorithm written from scratch against PySpark. In practice, +one may prefer to use the KMeans algorithm in MLlib, as shown in +examples/src/main/python/mllib/kmeans.py. + +This example requires NumPy (http://www.numpy.org/). +""" + +import sys + +import numpy as np +from pyspark import SparkContext + + +def parseVector(line): + return np.array([float(x) for x in line.split(' ')]) + + +def closestPoint(p, centers): + bestIndex = 0 + closest = float("+inf") + for i in range(len(centers)): + tempDist = np.sum((p - centers[i]) ** 2) + if tempDist < closest: + closest = tempDist + bestIndex = i + return bestIndex + + +if __name__ == "__main__": + if len(sys.argv) < 5: + print >> sys.stderr, "Usage: kmeans <master> <file> <k> <convergeDist>" + exit(-1) + sc = SparkContext(sys.argv[1], "PythonKMeans") + lines = sc.textFile(sys.argv[2]) + data = lines.map(parseVector).cache() + K = int(sys.argv[3]) + convergeDist = float(sys.argv[4]) + + kPoints = data.takeSample(False, K, 1) + tempDist = 1.0 + + while tempDist > convergeDist: + closest = data.map( + lambda p : (closestPoint(p, kPoints), (p, 1))) + pointStats = closest.reduceByKey( + lambda (x1, y1), (x2, y2): (x1 + x2, y1 + y2)) + newPoints = pointStats.map( + lambda (x, (y, z)): (x, y / z)).collect() + + tempDist = sum(np.sum((kPoints[x] - y) ** 2) for (x, y) in newPoints) + + for (x, y) in newPoints: + kPoints[x] = y + + print "Final centers: " + str(kPoints) |