No need I found this example
Thanks anyway
Workbook wb = new Workbook();
// CREATE SCATTER CHART
wb.Worksheets.Clear();
Worksheet ws = wb.Worksheets.Add("Sheet");
ws.Name = "Data";
Cells cells = ws.Cells;
cells["A1"].PutValue(DateTime.Now.AddMinutes(2));
cells["A2"].PutValue(DateTime.Now.AddMinutes(4));
cells["A3"].PutValue(DateTime.Now.AddMinutes(6));
cells["b1"].PutValue(4);
cells["b2"].PutValue(5);
cells["b3"].PutValue(6);
Charts charts = ws.Charts;
Chart chart = charts[charts.Add(ChartType.ScatterConnectedByLinesWithoutDataMarker, 10, 10, 20, 15)];
chart.NSeries.Add("Data!A1:A3", true);
chart.NSeries[0].XValues = "Data!B1:B3";