docs: def maxdiff(self):
          """
          m.maxdiff()   -- Compute maximum possible Euclidean distance to another motif.  (For normalizing?)
          """
          POW  = math.pow
          D = 0
          for i in range(self.width):
              _min = 100
              _max = -100
              for L in ACGT:
                  val = POW(2,self.logP[i][L])
                  if   val > _max:
                      _max  = val
                      _maxL = L
                  elif val < _min:
                      _min  = val
                      _minL = L
              for L in ACGT:
                  if L == _minL:
                      delta = 1-POW(2,self.logP[i][L])           #1-val
                      D = D + delta*delta
                  else:
                      D = D + POW( POW(2,self.logP[i][L]), 2)    #0-val
          return(math.sqrt(D))