Created
July 29, 2014 15:58
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PySpark countApproxDistinct
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| def error(estimate, size): | |
| return abs(estimate - size) / float(size) | |
| def uniform(): | |
| for x in xrange(100000): | |
| yield x % 100 | |
| rdd = sc.parallelize([x for x in uniform()]) | |
| assert(error(rdd._jrdd.rdd().countApproxDistinct(4, 0), 100) < 0.4) | |
| assert(error(rdd._jrdd.rdd().countApproxDistinct(8, 0), 100) < 0.1) | |
| https://github.com/apache/spark/blob/4c7243e109c713bdfb87891748800109ffbaae07/core/src/test/scala/org/apache/spark/rdd/RDDSuite.scala#L78-87 |
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