/**
* Given a JFreeChart dataset and a commons math function, return a JFreeChart dataset in which
* the original x values are now accompanied by the y values predicted by the function
*
* @param data input JFreeChart data set
* @param type one of the Fitter.FunctionType predefined functions
* @param parms parameters describing the function. These need to match the selected function or
* an IllegalArgumentEception will be thrown
* @return JFreeChart dataset with original x values and fitted y values.
*/
public static XYSeries getFittedSeries(XYSeries data, FunctionType type, double[] parms) {
XYSeries result = new XYSeries(data.getItemCount() * 10);
double minRange = data.getMinX();
double maxRange = data.getMaxX();
double xStep = (maxRange - minRange) / (data.getItemCount() * 10);
switch (type) {
case NoFit:
{
try {
XYSeries resCopy = data.createCopy(0, data.getItemCount() - 1);
return resCopy;
} catch (CloneNotSupportedException ex) {
return null;
}
}
case Pol1:
case Pol2:
case Pol3:
checkParms(type, parms);
PolynomialFunction polFunction = new PolynomialFunction(parms);
for (int i = 0; i < data.getItemCount() * 10; i++) {
double x = minRange + i * xStep;
double y = polFunction.value(x);
result.add(x, y);
}
break;
case Gaussian:
checkParms(type, parms);
Gaussian.Parametric gf = new Gaussian.Parametric();
for (int i = 0; i < data.getItemCount() * 10; i++) {
double x = minRange + i * xStep;
double[] gparms = new double[3];
System.arraycopy(parms, 0, gparms, 0, 3);
double y = gf.value(x, gparms) + parms[3];
result.add(x, y);
}
break;
}
return result;
}
