anchor.diff:          /// <param name="Color">The color for the data.</param>
           /// <param name="XTitle">The title of the X-axis.</param>
           /// <param name="YTitle">The title of the Y-axis.</param>
  -        static member Column(data:seq<('key :> key)*#value>,?Name,?Title,?Labels, ?Color,?XTitle,?YTitle) = 
  +        /// <param name="ColumnWidth">The width of columns versus whitespace as a percentage.</param>
  +        static member Column(data:seq<('key :> key)*#value>,?Name,?Title,?Labels, ?Color,?XTitle,?YTitle,?ColumnWidth:float) = 
  +           let gap = match ColumnWidth with 
  +                     | Some columnWidth -> Some (1.0 - columnWidth)
  +                     | _ -> None
              GenericChart.Create(data |> listen |> mergeLabels Labels |> makeItems (fun ((k,v),labelOpt) -> ColumnItem(valueToDouble v)), ColumnSeries(ValueField="Value"))
  -             |> Helpers.ApplyStaticAxis(typeof<'key>, Axes.AxisPosition.Bottom)
  +             |> Helpers.ApplyStaticAxis(typeof<'key>, Axes.AxisPosition.Bottom, ?gap = gap)
                |> Helpers.ApplyStyles(?Name=Name,?Title=Title,?Color=Color,?AxisXTitle=XTitle,?AxisYTitle=YTitle)
   
           /// <summary>Uses a sequence of columns to compare values across categories.</summary>
  
positive.code:         /// <param name="Color">The color for the data.</param>
          /// <param name="XTitle">The title of the X-axis.</param>
          /// <param name="YTitle">The title of the Y-axis.</param>
          static member Column(data:IObservable<#seq<#key * #value>>,?Name,?Title,(* ?Labels, *) ?Color,?XTitle,?YTitle) = 
              Chart.Column(NotifySeq.ofObservableReplacing data,?Name=Name,?Title=Title(* ,?Labels=Labels *),?Color=Color,?XTitle=XTitle,?YTitle=YTitle)
  
          /// <summary>Uses a sequence of columns to compare values across categories.</summary>
          /// <param name="data">The data for the chart. Each observation adds a data element to the chart.</param>
  
negative.code:         /// <param name="Color">The color for the data.</param>
          /// <param name="XTitle">The title of the X-axis.</param>
          /// <param name="YTitle">The title of the Y-axis.</param>
          /// <param name="ColumnWidth">The width of columns versus whitespace as a percentage.</param>
          static member Column(data:seq<#value>,?Name,?Title,?Labels, ?Color,?XTitle,?YTitle, ?ColumnWidth) = 
             Chart.Column(indexData data,?Name=Name,?Title=Title,?Labels=Labels, ?Color=Color,?XTitle=XTitle,?YTitle=YTitle, ?ColumnWidth=ColumnWidth)
  
  
          /// <summary>Generates a Histogram with reasonable defaults.</summary>
          /// <param name="data">The data for the chart.</param>
          /// <param name="Name">The name of the data set.</param>
          /// <param name="Title">The title of the chart.</param>
          /// <param name="Labels">The labels that match the data.</param>
          /// <param name="Color">The color for the data.</param>
          /// <param name="XTitle">The title of the X-axis.</param>
          /// <param name="YTitle">The title of the Y-axis.</param>
          static member Histogram(data:seq<#value>,?Name,?Title,?Color,?XTitle,?YTitle, ?LowerBound, ?UpperBound, ?Intervals) = 
              let data' = data |> Seq.map valueToDouble
              let lowerBound = match LowerBound with
                              | Some LowerBound -> LowerBound
                              | _ -> Seq.min data
              let upperBound = match UpperBound with
                              | Some UpperBound -> UpperBound
                              | _ -> Seq.max data
              let intervals = match Intervals with
                              | Some Intervals -> Intervals
                              | _ -> 30. // corresponds to what ggplot does
              let data'' = (binData data' lowerBound upperBound intervals) |> Seq.map (fun b -> b.Count)
              let labels = (binData data' lowerBound upperBound intervals) |> Seq.map (fun b -> b.LowerBound.ToString())
              Chart.Column(indexData data'',?Name=Name,?Title=Title,?Labels=Some labels, ?Color=Color,?XTitle=XTitle,?YTitle=YTitle, ?ColumnWidth=Some 0.95)
  
  #if INCOMPLETE_API
          /// <summary>Similar to the Pie chart type, except that it has a hole in the center.</summary>
  