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  1. Commons Math
  2. MATH-1370

Increase efficiency of EnumeratedDistribution#probability

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    Details

    • Type: Improvement
    • Status: Open
    • Priority: Minor
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: 4.0
    • Labels:
    • Flags:
      Patch

      Description

      There are lots of other low hanging fruit in the distribution package but unfortunately this is the only one I got to that day.

      In the EnumeratedDistribution case, the probability() method is currently O(N) where N denotes number of random variables, even though the random variables are fixed / known. This change makes probability() O(1). The unlikely worst case scenario now consumes slightly more than 2x the memory, but I do not think this would be an issue in the vast majority of cases.

      Original PR (incorrectly against master) here.

        Attachments

        1. enum-distribution-perf-patch.2
          7 kB
          Ryan Gaffney
        2. enum-distribution-perf-patch
          7 kB
          Ryan Gaffney

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            • Assignee:
              Unassigned
              Reporter:
              rG_ Ryan Gaffney
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              • Created:
                Updated: