How can avoid wiggling on my graph

[Wadigzon]

I have the option of SmoothLine set to true on my line series. How can avoid the wiggling on the line series? as shown on capture.jpg.

thanks for helping out.

[Peter]

Hi Wadigzon,

This is expected if your XAxis data is not sorted appropriately. Try to set sorting to the respective graph group. For this you may find useful the Group Explorer.

Regards,
Peter
Telerik

[Wadigzon]

Peter, 

I am doing on the code behind, more precisely at OnNeedDataSource(object sender, EventArgs e)
this is the snippet I am using to accomplish the setting of the group:

// create the time category group
var graphGroupTime = new GraphGroup();
graphGroupTime.Groupings.Add(new Grouping("=Fields.ServerCollectionTime"));
graphGroupTime.Name = "dateGroup";
graphGroupTime.Sortings.Add(new Sorting("=Fields.ServerCollectionTime", SortDirection.Asc));
// create the series identity group
var graphGroupId = new GraphGroup();
graphGroupId.Groupings.Add(new Grouping("=Fields.DeviceId"));
graphGroupId.Name = "idGroup";
graphGroupId.Sortings.Add(new Sorting("=Fields.DeviceId", SortDirection.Asc));
// line series
lineSeriesId = new LineSeries();
lineSeriesId.CategoryGroup = graphGroupTime;
lineSeriesId.CoordinateSystem = cartesianCoordinateSystem;
lineSeriesId.DataPointLabel = getFieldThresholdType(_reportModel.ThresholdType);
lineSeriesId.DataPointLabelStyle.Visible = false;
lineSeriesId.DataPointStyle.Visible = false;
lineSeriesId.Legend = "=ReportItem.Report.DataSource.GetDetectorName(Fields.DeviceId)"; // calls the function to get detector name
lineSeriesId.LegendFormat = "";
lineSeriesId.LineStyle.LineWidth = Unit.Pixel(1D);
lineSeriesId.MarkerMaxSize = Unit.Pixel(50D);
lineSeriesId.MarkerMinSize = Unit.Pixel(5D);
lineSeriesId.MarkerSize = Unit.Pixel(5D);
lineSeriesId.SeriesGroup = graphGroupId;
lineSeriesId.Size = null;
// smoothing of line, doesn't work great when there's too little data
lineSeriesId.SmoothLine = true;
lineSeriesId.X = "=Fields.ServerCollectionTime";
lineSeriesId.Y = "=(Fields.Speed)";

// graphSysDet defined as private Telerik.Reporting.Graph

// change legend settings
graphSysDet.Legend.Position = GraphItemPosition.BottomCenter;
graphSysDet.Legend.Style.SetGraphLegendStyle();
// adding series and groups to the graph
graphSysDet.Series.Add(lineSeriesId);
graphSysDet.SeriesGroups.Add(graphGroupId);
graphSysDet.CategoryGroups.Add(graphGroupTime);
// adding cartesian coordinates to graph
graphSysDet.CoordinateSystems.Add(cartesianCoordinateSystem);

are you sure is the sorting? because when I pick the "right" range of time (start and end) I get the correct smoothness.

[Wadigzon]

As you can see in these samples, one with smoothline set to false (capture_nosmooth.jpg) and one with smoothline set to true (capture_smooth.jpg). This later one has the wiggling starting at around 8:33AM and there's nothing in the data that suggest why this is happening as shown in the former picture (capture_nosmooth.jpg). And yes the data is already ordered by timestamp and the main key id. (deviceId in this case)

[Elian]

Hi Wadigzon,

The Graph engine draws a standard Bézier curve. When, such anomalies are observed, it usually is due to specifics of the data. For example, unsorted data, or overlapping points.

We cannot tell what happens in your case by just looking at the provided screenshots. If possible, open a support thread and send us a runnable sample (including data) so we can take 
 
Regards,
Elian
Telerik

[Wadigzon]

I got it figured out already. Yes it has to do with the data distribution. When there's multiple data points within the same time vicinity (less than a second away).