class TPaveStats: public TPaveText

  A PaveStats is a PaveText to draw histogram statistics
 The type of information printed in the histogram statistics box
  can be selected via gStyle->SetOptStat(mode).
  or by editing an existing TPaveStats object via TPaveStats::SetOptStat(mode).
  The parameter mode can be = ourmen  (default = 001111)
    n = 1;  name of histogram is printed
    e = 1;  number of entries printed
    m = 1;  mean value printed
    r = 1;  rms printed
    u = 1;  number of underflows printed
    o = 1;  number of overflows printed
  Example: gStyle->SetOptStat(11);
           print only name of histogram and number of entries.

 The type of information about fit parameters printed in the histogram
 statistics box can be selected via the parameter mode.
  The parameter mode can be = pcev  (default = 0111)
    v = 1;  print name/values of parameters
    e = 1;  print errors (if e=1, v must be 1)
    c = 1;  print Chisquare/Number of degress of freedom
    p = 1;  print Probability
  Example: gStyle->SetOptFit(1011);
        or this->SetOptFit(1011);
           print fit probability, parameter names/values and errors.

  WARNING: never call SetOptStat(000111); but SetOptStat(1111), 0001111 will
          be taken as an octal number !!
  NOTE that in case of 2-D histograms, when selecting just underflow (10000)
        or overflow (100000), the stats box will show all combinations
        of underflow/overflows and not just one single number!