seriesMapping seriesMapping = new SeriesMapping();
             foreach (IGroupDescriptor descriptor in chartGrid.GroupDescriptors)
            {
                seriesMapping.GroupingSettings.GroupDescriptors.Add(new ChartGroupDescriptor(getDataMemberName(descriptor)));
            }
            seriesMapping.ItemMappings.Add(new ItemMapping(lastGrouping , DataPointMember.XCategory));
            seriesMapping.ItemMappings.Add(new ItemMapping(lastGrouping , DataPointMember.LegendLabel));
            ChartAggregateFunction aggFunc = getChartAggregation(lbxFunction);
            mapping = new ItemMapping(lbxSumm.SelectedValue.ToString(), DataPointMember.YValue, aggFunc);
            DataColumn col = dt.Columns[lbxSumm.SelectedValue.ToString()];
            if (col != null) mapping.FieldType = col.DataType;
            seriesMapping.ItemMappings.Add(mapping);
            radChart1.DefaultSeriesDefinition = (ISeriesDefinition)getChartType();
            radChart1.ItemsSource = null;
            radChart1.SeriesMappings.Clear();
            radChart1.DefaultView.ChartLegend.UseAutoGeneratedItems = true;
            radChart1.DefaultSeriesDefinition.LegendDisplayMode = LegendDisplayMode.SeriesLabel; 
            DataTable dtSource = dt;
            radChart1.SeriesMappings.Add(seriesMapping);
            radChart1.ItemsSource = dtSource;