You can get away with a sparse representation of the vector, i.e. you can keep just the positions of the elements of the vector that are non-zero. Say the vector looks like: 

  (0, 1, 0, 0, 0, 1, 0, 0, 1, 0)

[download]
than you can encode it by a list containing just: 
  ( 1, 5, 8 )

[download]
This can be a huge space saver if the vector is really large. It is very easy to calculate the cosine between vectors in that representation: just count the number of common elements in the lists and divide by the square root of product of the length of each of the two lists.

Hope this helps, -gjb-

In reply to Re: Re: Re: Refining a 'vector space search'. by gjb
in thread Refining a 'vector space search'. by Seumas

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