Pie Chart - Labels Overlapping

[Sankar]

Hi Team

We are rendering pie chart with numerous slices which are dynamically generated based on the responses for the particular question, while we doing this pie slice's labels are overlapping. Kindly please provide the solution.

I have attached the expected format (Expected_Pie_Chart_Labels.png) as well as over lapped one(pie-slices-label-value-overlap.png).

We tried the suggestion which is mentioned on this link -

http://www.telerik.com/community/forums/reporting/telerik-reporting/pie-chart---connect-labels.aspx

When we applied IntelligentLabelsEnabled = true;  Its skipped few slice's labels which are causes overlapping. Please refer the attached image - piechart-no-overlap-but-label-value-skipped.png, there one of pie slice's response lablel was skipped.

Apart from this, we played around with decreasing the font size, increasing plot area, margin, label appearance property as well, but no use. 

One more issue we encountered here is, when we have 2 slices response's percentages are same, then only one leader line is rendering instead of two, this also causes over lapping even though we have enough space and less slices in pie. 

code snippet:

Telerik.Reporting.Processing.Chart chart = (Telerik.Reporting.Processing.Chart)groupHeaderSection.ChildElements.Find("chtItemPie", true)[0];
         Telerik.Reporting.Chart chartDef = (Telerik.Reporting.Chart)chart.ItemDefinition;
         chartDef.AutoLayout = true;
         chartDef.IntelligentLabelsEnabled = true;
         Telerik.Reporting.Charting.ChartSeries chartSeries = new Telerik.Reporting.Charting.ChartSeries();
         chartDef.Series.Clear();
         chartSeries.Type = Telerik.Reporting.Charting.ChartSeriesType.Pie;
         chartSeries.Appearance.LegendDisplayMode = Telerik.Reporting.Charting.ChartSeriesLegendDisplayMode.ItemLabels;
         chartDef.Legend.TextBlock.Visible = true;
         chartSeries.Appearance.ShowLabelConnectors = true;
         chartSeries.Appearance.StartAngle = 270;
         chartSeries.Appearance.ExplodePercent = 8;
         chartSeries.Appearance.LabelAppearance.Distance = 30;
         chartSeries.Appearance.DiameterScale = 0.85;
         chartSeries.Appearance.Border.Width = 2;
         chartSeries.Appearance.Border.PenStyle = System.Drawing.Drawing2D.DashStyle.Solid;

Version Detail: Telerik Reporting Q2 2012

Thanks
Sankar

[Stef]

Hello Sankar,

If by any chance you have not tested yet, try to set the DiameterScale property of the series to a smaller value, so labels can be gathered within the PlotArea, and set IntelligentLabelsEnabled to false.

I hope this helps.

All the best,
Stef
the Telerik team

[Sankar]

Hi Stef

Thanks for your response. Unfortunately DiameterScale doesn't help, we are facing over lapping issue even after we made change on diameterscale size (Please refer attached screenshot). Kindly please provide alternate solution.

P.S : In some cases, we are getting numerous slices in pie with respect to different responses (even 50,100,etc). Even for small number of slices, we are getting overlapping, wondering how Telerik can handle for the numerous slice's labels.

Thanks
Sankar

[Stef]

Hi Sankar,

What we can suggest you is to adjust the DiameterScale, LabelAppearance.Distance, StartAngel properties and the labels text to get a satisfying result.

Since the Chart item is obsolete and will not be supported, please consider switching to the new Graph item, which provides more options for label formatting through its data point label properties: DataPointLabel, DataPointLabelStyle. You can find attached an example report with Graph item.

I hope this helps.

Kind regards,
Stef
the Telerik team

[Venkatesh]

Hi Stef,

I am not able to find the option for label connector in your new version of Graph item (Q1 2013 SP1).

Ex: "ShowLabelConnectors" property is not available anywhere in graph instance.

Pls help me out how to achieve using Graph Item if possible.

Note: Trying to create PIE chart using graph item but NO option for label connector

Thanks,
S.Venkatesh

[Stef]

Hi Venkatesh,

Currently the Graph item does not support label connectors. This feature is planned to be implemented in a future release. There is no exact ETA for this feature as it depends on the priority of all tasks listed in our Roadmap.

Let us know if we can be of any further help for you.

All the best,
Stef
the Telerik team