String titleRef = new CellReference(sheet.getSheetName(), 0, 1, true, true).formatAsString();
tx.getStrRef().setF(titleRef);
// Category Axis Data
CTAxDataSource cat = ser.getCat();
CTStrData strData = cat.getStrRef().getStrCache();
// Values
CTNumDataSource val = ser.getVal();
CTNumData numData = val.getNumRef().getNumCache();
strData.setPtArray(null); // unset old axis text
numData.setPtArray(null); // unset old values
// set model
int idx = 0;
int rownum = 1;
String ln;
while((ln = modelReader.readLine()) != null){
String[] vals = ln.split("\\s+");
CTNumVal numVal = numData.addNewPt();
numVal.setIdx(idx);
numVal.setV(vals[1]);
CTStrVal sVal = strData.addNewPt();
sVal.setIdx(idx);
sVal.setV(vals[0]);
idx++;
XSSFRow row = sheet.createRow(rownum++);
row.createCell(0).setCellValue(vals[0]);
row.createCell(1).setCellValue(Double.valueOf(vals[1]));
}
numData.getPtCount().setVal(idx);
strData.getPtCount().setVal(idx);
String numDataRange = new CellRangeAddress(1, rownum-1, 1, 1).formatAsString(sheet.getSheetName(), true);
val.getNumRef().setF(numDataRange);
String axisDataRange = new CellRangeAddress(1, rownum-1, 0, 0).formatAsString(sheet.getSheetName(), true);
cat.getStrRef().setF(axisDataRange);
// updated the embedded workbook with the data
OutputStream xlsOut = xlsPart.getPackagePart().getOutputStream();
wb.write(xlsOut);
xlsOut.close();