/****************************************************************************
* GetfittingMetrics
* calculate the fitting parameters that the user is interested in
****************************************************************************/
public FittingMetrics GetFittingMetrics(LorentzParams lp, FFTSettings fftSettings)
{
FittingMetrics fm = new FittingMetrics
{
amplitude = lp.A / lp.gamma / lp.gamma + lp.up,
f0 = lp.f0
};
double ampPrime = 0;
switch (fftSettings.Fftstyle)
{
case 0: //Log (dB)
ampPrime = fm.amplitude - 3;
break;
case 1: // Log - Complex Conjugate (dB)
ampPrime = fm.amplitude - 3;
break;
case 2: // Magnitude (V)
ampPrime = fm.amplitude * 0.5;
break;
case 3: // Magnitude - Complex Conjugate (V)
ampPrime = fm.amplitude * 0.5;
break;
}
try
{
fm.f1 = fm.f0 + Math.Sqrt((lp.A + lp.gamma * lp.gamma * (lp.up - ampPrime)) / (ampPrime - lp.up));
fm.f2 = fm.f0 - Math.Sqrt((lp.A + lp.gamma * lp.gamma * (lp.up - ampPrime)) / (ampPrime - lp.up));
}
catch (Exception)
{
fm.f1 = 0;
fm.f2 = 0;
}
if (fm.f1 - fm.f2 > 0)
{
fm.Q = fm.f0 / (fm.f1 - fm.f2);
}
else
{
fm.Q = 0;
}
return(fm);
}
// LORENTZIAN FITTING //
/****************************************************************************
* GetLorentzParams
* Get lorentzian fitting parameters
****************************************************************************/
public void GetLorentzParams(FFTData fftData, LorentzSettings lorentzSettings, ref LorentzParams lorentzParams)
{
double[][] dataPoints = new double[][] { fftData.freq, fftData.fft };
LMA algorithm;
if (lorentzSettings.isYShiftLorentz)
{
LMAFunction lorentzShift = new LorenzianFunctionShift();
double[] startPoint = new double[4];
try
{
startPoint[0] = lorentzSettings.startPointLP.A;
}
catch (Exception)
{
startPoint[0] = 10;
}
try
{
startPoint[1] = lorentzSettings.startPointLP.f0;
}
catch (Exception)
{
startPoint[1] = 25;
}
try
{
startPoint[2] = lorentzSettings.startPointLP.gamma;
}
catch (Exception)
{
startPoint[2] = 1;
}
try
{
startPoint[3] = lorentzSettings.startPointLP.up;
}
catch (Exception)
{
startPoint[3] = 1;
}
algorithm = new LMA(lorentzShift, startPoint,
dataPoints, null, new GeneralMatrix(4, 4), 1d - 20, lorentzSettings.nIter);
algorithm.Fit();
lorentzParams.A = algorithm.Parameters[0];
lorentzParams.gamma = algorithm.Parameters[2];
lorentzParams.f0 = algorithm.Parameters[1];
lorentzParams.up = algorithm.Parameters[3];
}
else
{
LMAFunction lorentz = new LorenzianFunction();
double[] startPoint = new double[3];
try
{
startPoint[0] = lorentzSettings.startPointLP.A;
}
catch (Exception)
{
startPoint[0] = 10;
}
try
{
startPoint[1] = lorentzSettings.startPointLP.f0;
}
catch (Exception)
{
startPoint[1] = 25;
}
try
{
startPoint[2] = lorentzSettings.startPointLP.gamma;
}
catch (Exception)
{
startPoint[2] = 1;
}
algorithm = new LMA(lorentz, startPoint,
dataPoints, null, new GeneralMatrix(3, 3), 1d - 20, lorentzSettings.nIter);
algorithm.Fit();
lorentzParams.A = algorithm.Parameters[0];
lorentzParams.gamma = algorithm.Parameters[2];
lorentzParams.f0 = algorithm.Parameters[1];
lorentzParams.up = 0;
}
}
