1 REBIN
  Syntax: REBIN id [&idb]
          nbinxlo nbinxhi nbinx
          [nbinylo nbinyhi nbiny]
   where: id      is the  histogram identifier
          idb     is the (optional) secondary identifier
          nbinxlo is the first bin
          nbinxhi is the last bin
          nbinx   is the number of new bins

  Rebins a plot into `nbin' new bins from bin `nbinlo' to bin `nbinhi'. If
  `(nbinhi - nbinlo)' is not divisible by `nbin', `nbinhi' is rounded down
  until it is. Rebin works on 1 and 2-dimensional histograms.

