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More context for formula wanted

  1. Jan 31, 2012 #1
    For a set of values [itex]v_1,\dots,v_n[/itex] I recently stumbled over the formula

    [tex]\frac{1}{N^2} \sum_{i<j} (v_i-v_j)^2[/tex]

    where the sum is meant to be a double sum over j between 1 and N and i between 1 and j. First I thougth it should have something to do with variance. But this is obviously not the case. In my case, the [itex]v_i[/itex] are vectors, but this may or may not be important for the question:

    Does this formula ring any bells? Is it something with a name? Does it have an interesting simplification?

    Any hints appreciated.
    Last edited: Jan 31, 2012
  2. jcsd
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