SeriesMapping and weird behavior with XCategory

[Jatinder]

I have a SeriesMapping bound to IList<Tuple<string,int>>. The XAxis is bound to the string as a XCategory and the yaxis to the int.

Below is my xaml and my viewmodel.

The data is presented just as i want to but with a strange thing happening when i bound to a large list. It seems that the xcategory breaks down once the collection is past 200 items (in code below the for loop where i<190 - change that to say 210 and hell breaks loose). The xcategory gets messed up to numbers and not categorized anymore. See the 2 screenshots. 

<chart:RadChart x:Name="RadChart1" ItemsSource="{Binding Items}">

            <chart:RadChart.SeriesMappings>

                <charting:SeriesMapping>

                    <charting:SeriesMapping.SeriesDefinition>

                        <charting:ScatterSeriesDefinition ShowItemToolTips="True" LegendDisplayMode="None"/>

                    </charting:SeriesMapping.SeriesDefinition>

                    <charting:ItemMapping FieldName="Item1" DataPointMember="XCategory" />

                    <charting:ItemMapping FieldName="Item2" DataPointMember="YValue" />

                </charting:SeriesMapping>

            </chart:RadChart.SeriesMappings>

  

            <chart:RadChart.DefaultView>

                <charting:ChartDefaultView>

                    <charting:ChartDefaultView.ChartArea>

                        <charting:ChartArea ItemToolTipOpening="ChartArea_ItemToolTipOpening">

                            <charting:ChartArea.AxisX>

                                <charting:AxisX />

                            </charting:ChartArea.AxisX>

                            <charting:ChartArea.AxisY>

                                <charting:AxisY MinorTicksVisibility="Collapsed" />

                            </charting:ChartArea.AxisY>

                        </charting:ChartArea>

                    </charting:ChartDefaultView.ChartArea>

                </charting:ChartDefaultView>

            </chart:RadChart.DefaultView>

private Random ran;
        public DetailsViewModel()
        {
            ran = new Random();
            createName();
            createData();
        }

        private void createName()
        {
            names = new List<string>()
            {
                "One","two","three","four","five","six","seven","eight","nine","ten","One1","two1",
                "three1","four1","five1","six1","seven1","eight1","nine1","ten1","One2","two2","three2",
                "four2","five2","six2","seven2","eight2","nine2","ten2","One3","two3","three3",
                "four3","five3","six3","seven3","eight3","nine3","ten3"
            };
        }

        private void createData()
        {
            int count = names.Count;
            var t = new ObservableCollection<Tuple<string, int>>();
            for (int i = 0; i < 190; i++)
            {
                int val = ran.Next(5000);
                t.Add(new Tuple<string, int>(names[val % count], val));
            }
            Items = t;
        }

        public List<string> names { get; set; }
        public ObservableCollection<Tuple<string, int>> Items { get; set; }

[Bartholomeo Rocca]

Hello Jatinder,

200 is the default sampling threshold value for RadChart. You will need to set the SamplingThreshold value to 0 in the sampling settings to disable the built-in sampling mechanism (http://www.telerik.com/help/silverlight/radchart-features-sampling.html) and your chart should work as expected.


Greetings,
Bart.