Details

    • Type: New Feature
    • Status: Open
    • Priority: Major
    • Resolution: Unresolved
    • Affects Version/s: 0.5.0
    • Fix Version/s: None
    • Component/s: None
    • Labels:
      None
    • Environment:

      UDF, written in Pig 0.5 contrib/

    • Tags:
      contrib udf variance standard deviation

      Description

      I've implemented a UDF in Pig 0.5 that implements Algebraic and calculates variance in a distributed manner, based on the AVG() builtin. It works by calculating the count, sum and sum of squares, as described here: http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Parallel_algorithm

      Is this a worthwhile contribution? Taking the square root of this value using the contrib SQRT() function gives Standard Deviation, which is missing from Pig.

        Attachments

        1. var.patch
          11 kB
          rjurney
        2. PIG-1150.patch
          9 kB
          Jenny Thompson

          Activity

            People

            • Assignee:
              dvryaboy Dmitriy V. Ryaboy
              Reporter:
              russell.jurney Russell Jurney
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              Dates

              • Created:
                Updated: