RadChart shows wrong YValue. Does radchart resample YValues for a threshold ???

[Nurali]

Hello,
I have a RadChart control.  I would like to draw some important values.
I fixed X Axis range 0-720, And Y Axis range 0-240. The AutoRange properties are false.
I collect the ItemsSource data from a device. I think when I get some data over ~144 point RadChart re-samples the YValues and chart draws wrong(or rounded) values for me. And re-sampling  goes on while data come from my source. My Y axis values getting smaller !?

I use LineSeriesDefinition . I do not won't something like anti-aliasing, smoothing. Can it be a kind of chart issue ? 

I can see that I have "161" value as maximum(peak) YValue for my source and see it first. But when new values come I can see all values moved under 150 .  re-sampling done ??? Why my YValues getting smaller although my bound values still contains higher values such as 161. 

 <telerik:RadChart  x:Name="xRadChartECG1"  Grid.Column="1" ItemsSource="{Binding xSource}">
                                        <telerik:RadChart.DefaultView>
                                            <telerik:ChartDefaultView>
                                                <telerik:ChartDefaultView.ChartLegend>
                                                    <telerik:ChartLegend Visibility="Collapsed" />
                                                </telerik:ChartDefaultView.ChartLegend>
                                                <telerik:ChartDefaultView.ChartArea>
                                                    <telerik:ChartArea  EnableAnimations="False" LabelFormatBehavior="None" SmartLabelsEnabled="False" Background="White" >
                                                        <telerik:ChartArea.AxisY>
                                                            <telerik:AxisY AutoRange="False" MinValue="0" MaxValue="260"  AxisLabelsVisibility="Visible" StripLinesVisibility="Hidden" MinorTicksVisibility="Visible" MajorTicksVisibility="Visible" Visibility="Visible" />
                                                        </telerik:ChartArea.AxisY>
                                                        <telerik:ChartArea.AxisX >
                                                            <telerik:AxisX  IsDateTime="False" AxisLabelsVisibility="Visible" MajorTicksVisibility="Visible" Visibility="Visible" AutoRange="False" MinValue="0" MaxValue="720" />
                                                        </telerik:ChartArea.AxisX>
                                                        <telerik:ChartArea.ZoomScrollSettingsX>
                                                            <telerik:ZoomScrollSettings ScrollMode="None" />
                                                        </telerik:ChartArea.ZoomScrollSettingsX>
                                                    </telerik:ChartArea>
                                                </telerik:ChartDefaultView.ChartArea>
                                            </telerik:ChartDefaultView>
                                        </telerik:RadChart.DefaultView>
                                        <telerik:RadChart.SeriesMappings>
                                            <telerik:SeriesMapping>
                                                <telerik:SeriesMapping.SeriesDefinition>
                                                    <telerik:LineSeriesDefinition ShowPointMarks="False" ShowItemLabels="False">
                                                        <telerik:LineSeriesDefinition.Appearance>
                                                            <telerik:SeriesAppearanceSettings Fill="Green" Foreground="Green" Stroke="Green" StrokeThickness="1" />
                                                        </telerik:LineSeriesDefinition.Appearance>
                                                    </telerik:LineSeriesDefinition>
                                                </telerik:SeriesMapping.SeriesDefinition>
                                                <telerik:SeriesMapping.ItemMappings>
                                                    <telerik:ItemMapping FieldName="YValue"
                                             DataPointMember="YValue" />                                                  
                                                    <telerik:ItemMapping FieldName="Index"
                                             DataPointMember="XValue" />
                                                </telerik:SeriesMapping.ItemMappings>
                                            </telerik:SeriesMapping>
                                        </telerik:RadChart.SeriesMappings>
                                    </telerik:RadChart>
                                </Grid>

And the xSource is the below values . (same values comes for 10 times)

128
124
119
118
118
118
119
119
119
119
119
119
119
120
120
120
120
120
120
120
120
121
121
121
121
121
121
121
121
121
121
121
121
123
127
128
127
123
121
121
121
121
121
121
121
118
131
157
161
121
114
120
119
119
120
120
120
120
120
120
120
120
121
124
127
128
129
130
131
132
132

Thanks in advance

[Petar Marchev]

Hi Nurali,

The old RadChart control has a built-in sampling threshold of 200. You can disable sampling by setting the threshold to 0, like this: this.radChart1.SamplingSettings.SamplingThreshold = 0.

We generally suggest that you do not use the old RadChart but the new RadChartView instead. The new control has a much better performance, it is generally more flexible and is easy to set up.

Regards,
Petar Marchev
Telerik