Representation and definition of errors
                                                                   
      histogram/file 1 pawhists.hbook                                                                                   
      hrin  *                                                                                                           
      zone 2 3                                                                                                          
1     H/PL 110(1:50) E                                                                                           
2     H/PL 110(1:50) E1                                                                                          
3     H/PL 110(1:50) E2                                                                                          
      set htyp 245                                                                                                      
4     H/PL 110(1:50) E3                                                                                          
      set htyp 234                                                                                                      
5     H/PL 110(1:50) E4                                                                                          
      sigma err=array(100,0#200)                                                                                        
6     PUT/ERR 110 ERR                                                                                            
6     H/PL 110(1:50) E                                                                                           
      close 0                                                                                                           

1. Defaults error bars drawing.
2. Draw small lines at the end of the error bars. Note that the size of the tick marks at the end of the error bars is the minimum of the error on X and the marker size. If the errors on X are 0 no tick marks are drawn.
3. Draw error rectangles.
4. Draw a filled area through the end points of the vertical error bars.
5. Draw a smoothed filled area through the end points of the vertical error bars.
6. By default the errors on a histogram are the square root of the content. It is possible to define the errors with the command PUT/ERR .