XYSeries realseries = new XYSeries("Real Plot");
for (int j = 0; j < fdabs.length; j++) {
realseries.add(fdabs[j] + this.xoffset * i, spec.getElement(j).real() + this.yoffset * i);
}
dataset.addSeries(realseries);
XYSeries imagseries = new XYSeries("Imaginary Plot");
for (int j = 0; j < fdabs.length; j++) {
imagseries.add(fdabs[j] + this.xoffset * i, spec.getElement(j).imag() + this.yoffset * i);
}