This behavior for the category charts is basically because they are ideally expecting tabular data, see: http://help.infragistics.com//Help/NetAdvantage/DV/2009.2/CLR3.5/html/?page=SL_DV_xamWebChart_Column_Chart.html

In this case, and especially with silverlight, you provide this tabular data a column at a time in separate series objects, but the chart still only expects to use one column as its labels, and will not attempt to reorder, align, or fill in missing values between seperate series to account for missing or reordered labels.

You are welcome to request this as a feature: https://ko.infragistics.com/community/ideas

In the meantime, you may find the following sample to be quite useful. It shows how you can use some simple Linq queries to correlate your multiple series and fill in any labels that are missing from each series.

The Xaml:

<igChart:XamWebChart>
            <igChart:XamWebChart.Series>
                <igChart:Series ChartType="Column" 
                                DataSource="{Binding Data1}"
                                DataMapping="Label = Label; Value = Value"
                                />
                <igChart:Series ChartType="Column" 
                                DataSource="{Binding Data2}"
                                DataMapping="Label = Label; Value = Value"
                                />
            </igChart:XamWebChart.Series>
        </igChart:XamWebChart>

The code behind:

public class LabelUnioner
    {
        public static void UnionLabels<T>(
            IEnumerable<T> set1, IEnumerable<T> set2,
            Func<T, string> getLabel, 
            Func<string, string, int> compareLabels,
            Func<string, T> getDefault,
            out IEnumerable<T> unionedSet1, 
            out IEnumerable<T> unionedSet2)
        {
            var set1Labels = from item in set1 
                             select getLabel(item);
            var set2Labels = from item in set2 
                             select getLabel(item);

            //get the union of the labels from the two sets.
            var unionedLabels = set1Labels.Union(set2Labels);

            //sort the unioned labels using the provided comparison
            //function.
            List<string> sortedLabels = unionedLabels.ToList();
            sortedLabels.Sort((s1, s2) =>
            {
                return compareLabels(s1, s2);
            });

            //perform an outer join on such that any items that are
            //not represented in the unioned labels will have
            //a default item inserted.
            var newd1 = from l in sortedLabels
                        join d in set1 
                        on l equals getLabel(d) into g
                        from item in
                            g.DefaultIfEmpty(getDefault(l))
                        select item;
            //perform the same outer join for the other set.
            var newd2 = from l in sortedLabels
                        join d in set2 
                        on l equals getLabel(d) into g
                        from item in
                            g.DefaultIfEmpty(getDefault(l))
                        select item;
            unionedSet1 = newd1;
            unionedSet2 = newd2;
        }
    }

    public partial class MainPage
        : UserControl, INotifyPropertyChanged
    {
        public MainPage()
        {
            InitializeComponent();

            DataContext = this;

            ObservableCollection<TestDataItem> d1 =
                GetTestData1();
            ObservableCollection<TestDataItem> d2 =
                GetTestData2();


            IEnumerable<TestDataItem> newd1;
            IEnumerable<TestDataItem> newd2;

            LabelUnioner.UnionLabels<TestDataItem>(
                d1, d2,
                (item) => item.Label,
                (s1, s2) =>
                {
                    //sort the month values as date times
                    //rather than strings.
                    DateTime date1 = 
                        DateTime.ParseExact(s1, "MMM", 
                        CultureInfo.CurrentCulture);
                    DateTime date2 = 
                        DateTime.ParseExact(s2, "MMM",
                        CultureInfo.CurrentCulture);

                    return date1.Month.CompareTo(date2.Month);
                },
                (label) => new TestDataItem() 
                { 
                    Label = label, Value = 0 
                },
                out newd1, out newd2);


            Data1 = newd1;
            Data2 = newd2;
        }

        private IEnumerable<TestDataItem> data1;
        public IEnumerable<TestDataItem> Data1
        {
            get
            {
                return data1;
            }
            set
            {
                if (PropertyChanged != null)
                {
                    PropertyChanged(this,
                        new PropertyChangedEventArgs("Data1"));
                }
                data1 = value;
            }
        }
        private IEnumerable<TestDataItem> data2;
        public IEnumerable<TestDataItem> Data2
        {
            get
            {
                return data2;
            }
            set
            {
                if (PropertyChanged != null)
                {
                    PropertyChanged(this, 
                        new PropertyChangedEventArgs("Data2"));
                }
                data2 = value;
            }
        }

        private ObservableCollection<TestDataItem> GetTestData1()
        {
            ObservableCollection<TestDataItem> data =
                new ObservableCollection<TestDataItem>()
            {
                new TestDataItem() { Label = "Jan", Value = 2 },
                new TestDataItem() { Label = "Mar", Value = 3 },
                new TestDataItem() { Label = "Apr", Value = 6 }
            };

            return data;
        }

        private ObservableCollection<TestDataItem> GetTestData2()
        {
            ObservableCollection<TestDataItem> data = 
                new ObservableCollection<TestDataItem>()
            {
                new TestDataItem() { Label = "Feb", Value = 4 },
                new TestDataItem() { Label = "Mar", Value = 1 },
                new TestDataItem() { Label = "Apr", Value = 8 }
            };

            return data;
        }

        #region INotifyPropertyChanged Members

        public event PropertyChangedEventHandler PropertyChanged;

        #endregion
    }

    public class TestDataItem
    {
        public string Label { get; set; }
        public double Value { get; set; }
    }

-Graham

Apratim,

For this kind of series, the labels are going to be based of the first series in the chart, and there is the assumption that the seperate series will be aligned in terms of label, so something like this:

<igChart:XamWebChart>

            <igChart:XamWebChart.Series>

                <igChart:Series Label="Open"  ChartType="Column">

                    <igChart:Series.Animation>

                        <igChart:Animation />

                    </igChart:Series.Animation>

                    <igChart:Series.Fill>

                        <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">

                            <GradientStop Color="#FF358ECA" />

                            <GradientStop Color="#FF014E7C" Offset="1" />

                        </LinearGradientBrush>

                    </igChart:Series.Fill>

                    <igChart:Series.DataPoints>

                        <igChart:DataPoint Label="Jan" Value="25" />

                        <igChart:DataPoint Label="Feb" Value="0" />

                        <igChart:DataPoint Label="Mar" Value="14" />

                    </igChart:Series.DataPoints>

                </igChart:Series>

                <igChart:Series Label="Active" ChartType="Column" >

                    <igChart:Series.Animation>

                        <igChart:Animation />

                    </igChart:Series.Animation>

                    <igChart:Series.Fill>

                        <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">

                            <GradientStop Color="#FFA7D912" />

                            <GradientStop Color="#FF496100" Offset="1" />

                        </LinearGradientBrush>

                    </igChart:Series.Fill>

                    <igChart:Series.DataPoints>

                        <igChart:DataPoint Label="Jan" Value="0" />

                        <igChart:DataPoint Label="Feb" Value="15" />

                        <igChart:DataPoint Label="Mar" Value="18" />

                    </igChart:Series.DataPoints>

                </igChart:Series>

            </igChart:XamWebChart.Series>

        </igChart:XamWebChart>

probably renders more in the way you would expect. You can fill out missing values in either series with 0 values.

-Graham