[R] anyone know how to plot histograma and line in the same graph

[Xin]

Dear:

   I have two series data, which are:
      p1-obs p1-exp 
      13 13 
      20 23.296 
      22 18.139 
      19 14.972 
      10 12.576 
      16 10.658 
      8 9.0794 
      4 7.7625 
      3 6.6536 
      5 5.7141 
      7 4.9146 
      4 4.2321 
      0 3.648 
      4 3.1471 
      4 2.7168 
      2 2.3468 
      4 2.0283 
      2 1.7537 
      2 1.517 
      5 1.3127 
      1 1.1362 


And I want to plot one of series by historgram and the other by line.

such as the attachment.


Thanks

Xin