Action: Generates histogram ID2
as a copy of ID1, apart from the title.
Input parameter description:
CHTITL=' ' means that the old title is kept.
Action: Renames a histogram or Ntuple.
Input parameter description:
Action: Resets the contents of all channels of a histogram (and its projections) or Ntuple to zero and changes optionally the title.
Input parameter description:
ID=0 resets all existing histogram contents.
CHTITL=' ' means that the old title is kept.
Action: Deletes a histogram and releases the corresponding storage space.
Input parameter description:
ID=0 deletes all existing histograms.
See section 
in the introductory chapter for a simple
example of how to book, fill and print histograms.