> stem(x, par1, par2, par3)
  The decimal point is 1 digit(s) to the right of the |
   0 | 13455666677899
   1 | 01111133333444455555667888888899999
   2 | 0011111222333444445566667777777888
   3 | 1112222333444455555566667888
   4 | 0011222337889999
   5 | 0001223447778
   6 | 0111789
   7 | 
   8 | 016679
   9 | 1
  10 | 7
  11 | 0
  12 | 
  13 | 
  14 | 6
  15 | 
  16 | 
  17 | 
  18 | 
  19 | 5
  20 | 
  21 | 
  22 | 
  23 | 
  24 | 2
  25 | 0
  26 | 
  27 | 
  28 | 4
  29 | 
  30 | 3