histogram <xray-histogram-statement> end

<xray-histogram-statement> :==

  from=<real-space-object>
  --{The map for histogram calculation.}
  mbins=<integer>
  --{The number of bins for the histogram.}
  slot=<real>
  --{Slot width for the histogram. Default from map: (maximum-minimum)/mbins}
  rhomin=<real>
  --{Low density limit for the histogram.
     Default: the minimum density of the map.}
  rhomax=<real>
  --{High density limit for the histogram.
     Default: the maximum density of the map.}
  model=predicted|experimental
  --{Predicted: predicted histogram curve.
     Experimental: experimental histogram curve (default).}
  selection=<map selection>
  --{Select subset of map for analysis. Default=(all)}
  lowfraction=<real>
  --{If non-zero, a density level will be computed such that lowfraction%
     of the selected density points are below this level. The level is
     stored in the symbol $cutoff.}
  export=<filename>
  --{Export histogram to file.}
  hresolution=<real>
  --{Predict histogram at this highest resolution.
     This should be the high resolution limit used in computing the map.
     Default=0}
  data=<real> <real> ... <real>
  --{Assign histogram data for each bin. If read from a file
     the number of data points must be consistent with mbins.}
  match
  --{Perform histogram matching.
     Warning: this will overwrite the original map.}