Mahout
  1. Mahout
  2. MAHOUT-638

Stochastic svd's is not handling well all cases of sparse vectors

    Details

    • Type: Bug Bug
    • Status: Closed
    • Priority: Major Major
    • Resolution: Fixed
    • Affects Version/s: 0.5
    • Fix Version/s: 0.5
    • Component/s: Math
    • Labels:
      None

      Description

      The Mahout patch of the algorithm is not handling all types of sparse input efficiently. BtJob doesn't handle SequentialSparseVector in a way to pick only non-zero elements from initial input and QJob doesn't iterate over RandomAccessSparseVector correctly. With extremely sparse inputs (0.05% non-zero elements) that leads to a terrible inefficiency in the aforementioned jobs (QJob, BtJob).

      1. MAHOUT-638-2.patch
        30 kB
        Dmitriy Lyubimov
      2. MAHOUT-638-2.patch
        34 kB
        Dmitriy Lyubimov
      3. MAHOUT-638.patch
        3 kB
        Dmitriy Lyubimov
      4. MAHOUT-622-2.patch
        12 kB
        Dmitriy Lyubimov

        Activity

        Dmitriy Lyubimov created issue -
        Dmitriy Lyubimov made changes -
        Field Original Value New Value
        Attachment MAHOUT-638.patch [ 12474802 ]
        Dmitriy Lyubimov made changes -
        Status Open [ 1 ] Patch Available [ 10002 ]
        Sean Owen made changes -
        Comment [ I would drop most of the properties that specify versions. Defining a symbol that is used in one place doesn't really even save much. ]
        Sean Owen made changes -
        Comment [ bq. I would drop most of the properties that specify versions. Defining a symbol that is used in one place doesn't really even save much.

        I take it this is MAHOUT-622 comment? ]
        Sean Owen made changes -
        Comment [ {quote}
        I take it this is MAHOUT-622 comment?
        {quote}

        Err... yes.

        Or you could call it a space cadet comment.
        ]
        Dmitriy Lyubimov made changes -
        Attachment MAHOUT-638-2.patch [ 12476566 ]
        Dmitriy Lyubimov made changes -
        Attachment MAHOUT-622-2.patch [ 12476568 ]
        Dmitriy Lyubimov made changes -
        Attachment MAHOUT-638-2.patch [ 12476569 ]
        Dmitriy Lyubimov made changes -
        Status Patch Available [ 10002 ] Resolved [ 5 ]
        Resolution Fixed [ 1 ]
        Sean Owen made changes -
        Status Resolved [ 5 ] Closed [ 6 ]

          People

          • Assignee:
            Dmitriy Lyubimov
            Reporter:
            Dmitriy Lyubimov
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            Dates

            • Created:
              Updated:
              Resolved:

              Development