Understanding equations with multiple summations

Discussion in 'General Math' started by crd319, Jun 18, 2008.

  1. crd319

    crd319 Guest

    I am working on a project which involves comparing two regions of an
    image by means of a "G statistic" The equation I am to use is as

    E_(variable) denotes a Sigma (Summation) with variable as its


    s,m are two histograms (256x8 2D histograms)
    i is a bin number
    f_i is the frequency at bin i

    The equation, as defined in the paper I'm using, is:

    G = 2*( [E_s,m E_i f_i log f_i] -[E_s,m (E_i f_i) log (E_i f_i)] -
    [E_i (E_s,m f_i) log (E_s,m f_i) ] +
    [(E_s,m E_i f_i) log (E_s,m E_i f_i) ]

    I am trying to perform this comparison within a computer program but I
    am unsure of the logical flow of it, mostly since there are 3
    variables (s,m,i) but only one is explicitly shown to be used. I am
    not familiar with this complex of a problem so if anyone could help my
    try and decipher this equation, I would be gratefuk
    crd319, Jun 18, 2008
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  2. Written in which language?
    I suggest you ask in comp.lang.<the language in question>.
    Frederick Williams, Jun 19, 2008
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  3. crd319

    crd319 Guest

    Right now, Im less worried about physical implementation and more just
    trying to understand the equation. If I can get the theory, I can
    figure out the code.

    crd319, Jun 20, 2008
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