code: def distATT(x1,y1,x2,y2):
      
      xd = x2 - x1
      yd = y2 - y1
      rij = math.sqrt((xd*xd + yd*yd) /10.)
      tij = int(rij + .5)
      if tij < rij:
          return tij + 1
      else:
          return tij
docs: Compute the ATT distance between two points (see TSPLIB documentation)