// Input data: values_Y and values_X are double arrays
Chart chart = new Chart();
chart.Left = 0;
chart.Width = Unit.FromCentimeter(16);
chart.Height = Unit.FromCentimeter(12);
Series series = chart.SeriesCollection.AddSeries();
series.ChartType = ChartType.Line;

series.Add(values_Y);
XSeries xseries = chart.XValues.AddXSeries();

foreach (var value in values_X)
{
     xseries.Add(value.ToString());
}

chart.XAxis.MajorTick = 10.0;   // Setting the MajorTick here which does not have any effect !
chart.XAxis.MajorTickMark = TickMarkType.Outside;
chart.XAxis.Title.Caption = "X-Axis";


chart.YAxis.MajorTick = 10.0;
chart.YAxis.MajorTickMark = TickMarkType.Outside;
chart.YAxis.HasMajorGridlines = true;
chart.PlotArea.LineFormat.Color = Colors.DarkGray;
chart.PlotArea.LineFormat.Width = 1;

document.LastSection.Add(chart);

XSeries xseries = chart.XValues.AddXSeries();
string[] xSeriesText = new string[dataSet.Length];
 for (int i = 0; i < dataSet.Length; i++)
{
     xSeriesText[i] = ((i%10)==0) ? i.ToString() : string.Empty;
}
 xseries.Add(xSeriesText);