Hi
I have a requirement to show the top 10 pie slices and group all the rest together in one large slice. I need to add all the values for the large slice together, but I'm having difficulty accessing the values. Any tips/pointers are welcome. Thanks.
Here's my code:

double dLargeSliceValue = 0;
for (int i = pieSeries.GetDataPointCount(); i >= 0; i--)
  {
    dLargeSliceValue = dLargeSliceValue + pieSeries.Values[i].Value;
    if (i>9)
      { //group
        //add to value
        dLargeSliceValue = dLargeSliceValue + (double)pieSeries.Values[i]; /* this does not work */
        //remove initial slice
        pieSeries.RemoveDataPointAt(i);
      }
      else
      { //assign color
        pieSeries.FillStyles[i] = new NColorFillStyle(colorList[i]);
      }
  }
  // add a large slice
   NDataPoint dp = new NDataPoint(dLargeSliceValue, groupLabel);
   dp[DataPointValue.PieDetachment] = 1;
   pieSeries.AddDataPoint(dp);

Hi Alan,

The most obvious problem with that code is that the index is incorrect:
int i = pieSeries.GetDataPointCount()
initializes i with an index which is outside the values bounds - it should be:
int i = pieSeries.GetDataPointCount() - 1

We tested with the following code:

   nChartControl1.Panels.Clear();

   NPieChart pieChart = new NPieChart();
   nChartControl1.Panels.Add(pieChart);

   NPieSeries pieSeries = new NPieSeries();
   pieChart.Series.Add(pieSeries);

   for (int i = 0; i < 20; i++)
   {
    pieSeries.Values.Add(i);
   }

   double dLargeSliceValue = 0.0;
   NChartPalette chartPalette = new NChartPalette(ChartPredefinedPalette.Autumn);
   List<Color> colorList = chartPalette.SeriesColors;

   for (int i = pieSeries.GetDataPointCount() - 1; i >= 0; i--)
   {
    if (i > 9)
    { //group
     //add to value
     dLargeSliceValue = dLargeSliceValue + (double)pieSeries.Values[i]; /* this does not work */
     //remove initial slice
     pieSeries.RemoveDataPointAt(i);
    }
    else
    { //assign color
     pieSeries.FillStyles[i] = new NColorFillStyle(colorList[i % colorList.Count]);
    }
   }
   // add a large slice
   NDataPoint dp = new NDataPoint(dLargeSliceValue, "Grouped");
   dp[DataPointValue.PieDetachment] = 1;
   pieSeries.AddDataPoint(dp);

and it was working properly. Let us know if you meet any problems or have any questions.

Best Regards,
Nevron Support Team

Great, that worked, thanks!