public void setValueTo(String widgName, double val) {
        String str = Double.toString(val);
        KmaxWidget widg = tlsh.getKmaxWidget(widgName);
        widg.setProperty("TEXT", str);
} // setValueTo

public void ROI(KmaxWidget widget){

        setValueTo("SUM", hist1D.getRegionSum(null));
        setValueTo("CENTROID", hist1D.getRegionCentroid(null)[0]);
        setValueTo("FWHM", hist1D.getRegionFWHM(null)[0]);
}//ROI

double number = 10.123124123;
String str = String.format("%.3f", number); // 3 decimals

System.out.println(str); // 10,123