//Instantiate Presentation class that represents PPTX file
Presentation pres = new Presentation("data/pptx4j/AsposeChart.pptx");

//Access first slide
ISlide sld = pres.getSlides().get_Item(0);

// Add chart with default data
IChart chart = (IChart)sld.getShapes().get_Item(0);

//Setting the index of chart data sheet
int defaultWorksheetIndex = 0;

//Getting the chart data worksheet
IChartDataWorkbook fact = chart.getChartData().getChartDataWorkbook();

//Changing chart Category Name
fact.getCell(defaultWorksheetIndex, 1, 0, "Modified Category 1");
fact.getCell(defaultWorksheetIndex, 2, 0, "Modified Category 2");


//Take first chart series
IChartSeries series = chart.getChartData().getSeries().get_Item(0);

//Now updating series data
fact.getCell(defaultWorksheetIndex, 0, 1, "New_Series1");//modifying series name
series.getDataPoints().get_Item(0).getValue().setData (90);
series.getDataPoints().get_Item(1).getValue().setData ( 123);
series.getDataPoints().get_Item(2).getValue().setData ( 44);

//Take Second chart series
series = chart.getChartData().getSeries().get_Item(1);

//Now updating series data
fact.getCell(defaultWorksheetIndex, 0, 2, "New_Series2");//modifying series name
series.getDataPoints().get_Item(0).getValue().setData (23);
series.getDataPoints().get_Item(1).getValue().setData ( 67);
series.getDataPoints().get_Item(2).getValue().setData ( 99);


//Now, Adding a new series
chart.getChartData().getSeries().add(fact.getCell(defaultWorksheetIndex, 0, 3, "Series 3"), chart.getType());

//Take 3rd chart series
series = chart.getChartData().getSeries().get_Item(2);

//Now populating series data
series.getDataPoints().addDataPointForBarSeries(fact.getCell(defaultWorksheetIndex, 1, 3, 20));
series.getDataPoints().addDataPointForBarSeries(fact.getCell(defaultWorksheetIndex, 2, 3, 50));
series.getDataPoints().addDataPointForBarSeries(fact.getCell(defaultWorksheetIndex, 3, 3, 30));

chart.setType(ChartType.ClusteredCylinder);

// Save presentation with chart
pres.save("data/pptx4j/ChartModified-Aspose.pptx", SaveFormat.Pptx);

// Input file
String inputfilepath = "data/pptx4j/pptx-chart.pptx";

// The names of the parts which will be edited
// Alter these to match what is in your input pptx
// .. the chart
String chartPartName = "/ppt/charts/chart1.xml";
// .. the xlsx
String xlsPartName = "/ppt/embeddings/Microsoft_Excel_Sheet1.xlsx";

// Output file
String outputfilepath = "data/pptx4j/ChartModified-Pptx4j.pptx";

// Values to change
Random rand = new Random();

String firstValue  = String.valueOf(rand.nextInt(99));
String secondValue = String.valueOf(rand.nextInt(99));

// Open the PPT template file
PresentationMLPackage ppt = (PresentationMLPackage) OpcPackage
    .load(new java.io.File(inputfilepath));

/*
 * Get the Chart object and update the values. Afterwards, we'll update 
 * the associated spreadsheet so that the data is synchronized.
 */
Chart chart = (Chart) ppt.getParts().get(new PartName(chartPartName));

List<Object> objects = chart.getJaxbElement().getChart().getPlotArea()
        .getAreaChartOrArea3DChartOrLineChart();

for (Object object : objects) {

    if (object instanceof CTBarChart) {

        List<CTBarSer> ctBarSers = ((CTBarChart) object).getSer();

        for (CTBarSer ctBarSer : ctBarSers)
        {
            List<CTNumVal> ctNumVals = ctBarSer.getVal().getNumRef().getNumCache().getPt();
            for (CTNumVal ctNumVal : ctNumVals)
            {
                System.out.println("ctNumVal Val BEFORE: " + ctNumVal.getV());
                if (ctNumVal.getIdx() == 0) {
                    ctNumVal.setV(firstValue);
                }
                else if (ctNumVal.getIdx() == 1) {
                    ctNumVal.setV(secondValue); 
                }
                System.out.println("ctNumVal Val AFTER: " + ctNumVal.getV());
            }
        }
    }
}

/*
 * Get the spreadsheet and find the cell values that need to be updated
 */

EmbeddedPackagePart epp  = (EmbeddedPackagePart) ppt
    .getParts().get(new PartName(xlsPartName));

if (epp==null) {
    throw new Docx4JException("Could find EmbeddedPackagePart: " + xlsPartName);
}

InputStream is = BufferUtil.newInputStream(epp.getBuffer());

SpreadsheetMLPackage spreadSheet = (SpreadsheetMLPackage) SpreadsheetMLPackage.load(is);

Map<PartName,Part> partsMap = spreadSheet.getParts().getParts();         
Iterator<Entry<PartName, Part>> it = partsMap.entrySet().iterator();

while(it.hasNext()) {
    Map.Entry<PartName, Part> pairs = it.next();

    if (partsMap.get(pairs.getKey()) instanceof WorksheetPart) {

        WorksheetPart wsp = (WorksheetPart) partsMap.get(pairs.getKey()) ;

        List<Row> rows = wsp.getJaxbElement().getSheetData().getRow();

        for (Row row : rows) {
            List<Cell> cells = row.getC();
            for (Cell cell : cells)
            {
                if (cell.getR().equals("B2") && cell.getV() != null) {
                    System.out.println("B2 CELL VAL: " + cell.getV());
                    // change the B2 cell value
                    cell.setT(STCellType.STR);
                    cell.setV(firstValue);
                }
                else if (cell.getR().equals("B3") && cell.getV() != null) {
                    System.out.println("B3 CELL VAL: " + cell.getV());
                    // Change the B3 cell value
                    cell.setT(STCellType.STR);
                    cell.setV(secondValue);
                }
            }                   
        }
    }
}

/*
 * Convert the Spreadsheet to a binary format, set it on the 
 * EmbeddedPackagePart, add it back onto the deck and save to a file.
 *  
 */     
ByteArrayOutputStream baos = new ByteArrayOutputStream();

SaveToZipFile saver = new SaveToZipFile(spreadSheet);

saver.save(baos);
epp.setBinaryData(baos.toByteArray());

// Write the new file to disk
ppt.save(new java.io.File(outputfilepath));