15.11.14  Example 

Say you wish to find the frequency distribution of a set of student grades
in 5 point steps.  The following will do the job:
     TD:SET ORDER X
          (Enter grades)
     TD:Grade1;  Grade2;  Grade3.....
     TD:Graden;.......
     TD:BIN BY 5 (now do the binning)
     TD:HISTOGRAM
Suppose  you  wish  to  add  together  2 HBOOK histograms.  Each histogram
contains counts, but the X spacing is different.
     TD:SET HIST HBOOK ID=n1
     TD:SET HIST ID=n2 APPEND
          You now have both hists in memory.
     TD:BIN NORMAL=OFF
You  now  have both histograms added together.  If both histograms had the
same X values/bin then the result will have  the  same  X  values  as  the
original.