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Subject: Re: fast normalization

Author: Charles Roberson

Date: 07:28:53 10/31/03

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On October 31, 2003 at 10:06:53, Ricardo Gibert wrote:

>On October 31, 2003 at 09:04:41, Charles Roberson wrote:
>
>>
>>   I have a list of numbers that I wanted to normalize to the range of 0-100.
>>   The numbers are integers so the obvious thought is
>>      find largest
>>      foreach number
>>         number = number*100/largest
>
>Since the "/largest" does not change within the loop, it can be moved outside
>the loop. In this way, only 1 division is performed for all the numbers of the
>set. Acceptable if the set is large. Making this idea work requires some
>elaboration, but is quite workable.
>

     Algebra allows factoring out the 100/largest and creating a loop invariant
  constant. However, largest can be very big and we are using integer
  arithmetic. Thus, a large largest can make 100/largest = 0.





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