 options and the fit data range.
    <li>
  <tt>ROOT::Fit::FillData</tt>: function for filling the fit data from the histogram data objects. Used for fitting an histogram using the <tt>ROOT::Fit::Fitter</tt> class.
    <li>
    <tt>ROOT::Fit::UnBinFit</tt>:: function for fitting an unbinned data sets, for example obtained from TTree data.
  </li>
  </ul>


  <h4>TBackCompFitter</h4>
  New class providing a backward compatible implementation of the
     <tt>TVirtualFitter</tt> using the new fitting class. It