18.337 WebMeeting


Message from: Steven G. Johnson (stevenj@MIT.EDU)
About: Rules Clarifications

Fri, 11 Apr 97 00:20:23 EDT

  • Next message: Russell Schwartz: "Rules Clarifications"
    Several ambiguities were brought to my attention by eakeyes@MIT.EDU.
    Thanks, Edward!

    * Memory Usage Limitations:

    There are no limitations on the memory usage of your code. (Of course, if your
    code exceeds the memory available on the machine, it is your own fault.) You
    are free to allocate whatever temporary storage you like and do whatever you
    want with it, as long as all computations/transformations on the data are included
    in the timing.

    * Initializing C

    In the pseudocode, I mentioned initializing C. This was an oversight...C does not
    need to be initialized since it is overwritten with A*B.

    * Matrix Sizes

    I was asked to give an estimate of an order of magnitude for the matrix sizes. I was not
    planning to pick the matrix sizes for the contest myself, since I will be submitting an
    entry. However, matrix dimensions from 2^7 to about 2^12 rows/columns seem like
    reasonable values.

    * Numeric Data Type

    All data and computations should be in double precision.

    * Array Initializations--Sparse Matrices?

    You can initialize the arrays A and B to whatever you want (some constant value
    seems simplest, and random data seems good for testing), but you may not take
    advantage of a special initialization. Also, this is not a sparse matrix multiply
    contest; don't take advantage of zeros in your matrices. In other words, pretend
    that your matrices are filled with random non-zero data, even if they aren't.

    Of course, there is one restriction...entries of A and B must be initialized to valid
    floating point values. If you start doing floating point operations on NaN's, the
    timing results will be completely bogus (and your code will be very slow anyway).

    Cordially,
    Steven G. Johnson

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