StackedColumn chart shows weird column width

Question

It's really a simple task I am doing here. I need to put two series as StackedColumn and 1 Point series together in one ChartArea. Below is the code. Each series only has three DataPoints for test purpose.

The resulting chart looks in the first picture below. The width of the stacked column looks slim. If I change the data of the Point series to 1 point per month over the three months, the resulting stacked column width looks just fine (picture 2). Also, if I use Column instead of StackedColumn for s1 and s2, the column width will be all good (Picture 3), no matter what data in the Point series s3.

Can anybody explain what's going on here and how to fix the problem in picture 1.

        Series s1 = new Series("s1");            
        s1.ChartType = SeriesChartType.StackedColumn;
        //s1.ChartType = SeriesChartType.Column;
        s1.XValueType = ChartValueType.Date;
        s1.Points.Add(new DataPoint((new DateTime(2016, 1, 1)).ToOADate(), 100));
        s1.Points.Add(new DataPoint((new DateTime(2016, 2, 1)).ToOADate(), 100));
        s1.Points.Add(new DataPoint((new DateTime(2016, 3, 1)).ToOADate(), 100));

        Series s2 = new Series("s2");
        s2.ChartType = SeriesChartType.StackedColumn;
        //s2.ChartType = SeriesChartType.Column;
        s2.XValueType = ChartValueType.Date;
        s2.Points.Add(new DataPoint((new DateTime(2016, 1, 1)).ToOADate(), 200));
        s2.Points.Add(new DataPoint((new DateTime(2016, 2, 1)).ToOADate(), 200));
        s2.Points.Add(new DataPoint((new DateTime(2016, 3, 1)).ToOADate(), 200));

        Series s3 = new Series("s3");
        s3.ChartType = SeriesChartType.Point;
        s3.XValueType = ChartValueType.Date;
        s3.Points.Add(new DataPoint((new DateTime(2016, 1, 1)).ToOADate(), 400));
        s3.Points.Add(new DataPoint((new DateTime(2016, 1, 4)).ToOADate(), 400));
        s3.Points.Add(new DataPoint((new DateTime(2016, 1, 7)).ToOADate(), 400));
        //s3.Points.Add(new DataPoint((new DateTime(2016, 1, 1)).ToOADate(), 400));
        //s3.Points.Add(new DataPoint((new DateTime(2016, 2, 4)).ToOADate(), 400));
        //s3.Points.Add(new DataPoint((new DateTime(2016, 3, 7)).ToOADate(), 400));

        cht.Series.Add(s1); cht.Series.Add(s2); cht.Series.Add(s3);

        cht.ChartAreas[0].AxisX.IntervalType = DateTimeIntervalType.Months;
        cht.ChartAreas[0].AxisX.Interval = 1;
        cht.ChartAreas[0].AxisX.MajorGrid.Enabled = false;
        cht.ChartAreas[0].AxisY.MajorGrid.Enabled = false;

Answer 1

As per MSDN on StackedColumn:

Stacked series must be aligned. Otherwise, data points will be rendered incorrectly. For more information, see Aligning Data.

Here is says:

Two Series are considered to be aligned if they have the same number of data points and the same data in their corresponding X values.

Since the Point and the StackedColumn series' are not aligned, the columns make room for the missing columns.

This can't really be avoided if you want more points to show than stacked columns because :

Number of series : One or more (multiple series are stacked).

You could try to overlay a second ChartArea with the first one and then add a Point series. See here for two examples! It may take some test to find the right way to set up the second chartarea and its axes..