public static QuantityTrackWriter getInstance(OutputStream out,
String name,
TrackAnalyzer.Quantity q,
TrackAnalyzer ta) throws SAXException, IOException{
ValueFunction vf = ColorFunctionFactory.createValueFunction(ta, q);
UnivariateRealFunction hue = null;
double ymin = Double.POSITIVE_INFINITY;
double ymax = Double.NEGATIVE_INFINITY;
if (q == TrackAnalyzer.Quantity.Bearing){