def g(number_of_links, size_x, size_y)
      a = (size_x + size_y) ** p
      b = size_x ** p
      c = size_x ** p

      number_of_links / (a - b - c)
    end
def g(number_of_links, size_x, size_y)
      a = (size_x + size_y) ** p
      b = size_x ** p
      c = size_x ** p

      number_of_links / (a - b - c)
    end
th should be >= 0 and <= 1
   0 means all datapoints are neighbours
   1 means no datapoints are neighbours
   (proximity)