// For complete examples and data files, please go to https://github.com/aspose-cells/Aspose.Cells-for-Java
// The path to the documents directory.
String dataDir = Utils.getSharedDataDir(ModifyLineChart.class) + "charts/";

// Instantiating a Workbook object
Workbook workbook = new Workbook(dataDir + "book1.xls");

// Obtaining the reference of the first worksheet
WorksheetCollection worksheets = workbook.getWorksheets();
Worksheet sheet = worksheets.get(0);

// Load the chart from source worksheet
Chart chart = sheet.getCharts().get(0);

// Adding NSeries (chart data source) to the chart ranging from "A1"
// cell to "B3"
SeriesCollection serieses = chart.getNSeries();
serieses.add("{20,40,90}", true);
serieses.add("{110,70,220}", true);

// Saving the Excel file
workbook.save(dataDir + "ModifyLineChart_out.xls");

// Print message
System.out.println("Line chart is successfully modified.");