Thread: Running my program.....estimated to take 55 hrs...

  1. 03-18-2005 #1
    AssistMe
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    Running my program.....estimated to take 55 hrs...

    I've finally completed my assignment of writing a statistical program to select features.....

    When I used small datasets of about 5 features...the program works perfect...but when I tried the program with a dataset of 150,000 features......the estimated time to complete the calculation is about 55 hours.......

    After 1 hr, only 1.3K of features are calculated...
    and the CPU seems to be unusually warm when the program is running.....I can feel hot air constantly blowing towards my hand when I'm using the mouse.....

    (I used debugger to estimate the time to load...)

    So can you people tell me your experience, what are the possible reasons which cause the program to run so slow...??

    _____
  2. 03-18-2005 #2
    IfYouSaySo
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    google "Big Oh notation".
    The crows maintain that a single crow could destroy the heavens. Doubtless this is so. But it proves nothing against the heavens, for the heavens signify simply: the impossibility of crows.
  3. 03-18-2005 #3
    InvariantLoop
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    When no one helps you out. Call google();
  4. 03-18-2005 #4
    MadCow257
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    What exactly are you trying to do? It sounds like you are brute forcing a problem when there might be a much more efficient algorithm.
  5. 03-18-2005 #5
    pianorain
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    Heh, reminds me of the first mathematical model I made for my job. It was estimated to take 147 years to finish. I optimized it down to just over 8 years. It should be finished in 2012.
    If I did your homework for you, then you might pass your class without learning how to write a program like this. Then you might graduate and get your degree without learning how to write a program like this. You might become a professional programmer without knowing how to write a program like this. Someday you might work on a project with me without knowing how to write a program like this. Then I would have to do you serious bodily harm. - Jack Klein
  6. 03-18-2005 #6
    Quantum1024
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    Quote Originally Posted by pianorain
    Heh, reminds me of the first mathematical model I made for my job. It was estimated to take 147 years to finish. I optimized it down to just over 8 years. It should be finished in 2012.
    haha I hope your not holding your breath.
  7. 03-18-2005 #7
    pianorain
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    After I went to my boss and showed him a proof that took all of three hours to write up, he accepted that instead of the program results.
    If I did your homework for you, then you might pass your class without learning how to write a program like this. Then you might graduate and get your degree without learning how to write a program like this. You might become a professional programmer without knowing how to write a program like this. Someday you might work on a project with me without knowing how to write a program like this. Then I would have to do you serious bodily harm. - Jack Klein
  8. 03-18-2005 #8
    VirtualAce
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    With new machine speeds no program should ever take that long.
  9. 03-18-2005 #9
    Salem
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    http://vision.eng.shu.ac.uk/bala/c/c...imization.html
    Consider the first two points VERY carefully.

    > what are the possible reasons which cause the program to run so slow...??
    Well using a bubble sort on such a large data sample rather than qsort will be a real killer.
    Like the link says, choose good algorithms is the biggest win you will ever make.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
  10. 03-18-2005 #10
    quzah
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    Quote Originally Posted by Bubba
    With new machine speeds no program should ever take that long.
    I guess you've never heard of program that calculate huge prime numbers. Or of the SETI project. Or of... need I go on?

    Quzah.
    Hope is the first step on the road to disappointment.
  11. 03-20-2005 #11
    AssistMe
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    Quote Originally Posted by pianorain
    Heh, reminds me of the first mathematical model I made for my job. It was estimated to take 147 years to finish. I optimized it down to just over 8 years. It should be finished in 2012.

    Wow...that was really something man..!!! lol~ Btw, How do you optimize the codes...??

    _____
  12. 03-20-2005 #12
    AssistMe
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    Should I be using bubble sort...??

    _____
  13. 03-20-2005 #13
    Dave_Sinkula
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    >Should I be using bubble sort...??

    No.
    7. It is easier to write an incorrect program than understand a correct one.
    40. There are two ways to write error-free programs; only the third one works.*
  14. 03-20-2005 #14
    AssistMe
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    All right..then does using qsort helps to optimize my codes to certain levels...??

    _____
  15. 03-21-2005 #15
    sand_man
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    Nice link Salem. I can learn a few things here
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