/// <summary>
/// Kaiser Window Filter
/// </summary>
/// <param name="inputData">Input waform data</param>
/// <param name="f">Band edges</param>
/// <param name="a"> Desired amplitude on the bands define by f</param>
/// <param name="dev">Passband ripple and stopband attenuation</param>
/// <param name="fs">Samplerate</param>
/// <returns>Output waveform data</returns>
public static double[] Kaiser(double[] inputData, double[] f, double[] a, double[] dev, double fs)
{
MWNumericArray inputDataMatlab = inputData;
MWNumericArray fMatlab = f;
MWNumericArray aMatlab = a;
MWNumericArray devMatlab = dev;
MWArray fsMatlab = fs;
MWArray[] resultMatlab;
double[,] result2D;
double[] result;
DSPClass dspTask = new DSPClass();
resultMatlab = dspTask.Kaiser(1, inputDataMatlab, fMatlab, aMatlab, devMatlab, fsMatlab);
result2D = (double[, ])resultMatlab[0].ToArray();
result = new double[result2D.Length];
Buffer.BlockCopy(result2D, 0, result, 0, result2D.Length * sizeof(double));
return(result);
}
/// <summary>
/// FFT Spectrum
/// </summary>
/// <param name="Wave">Input Wave</param>
/// <param name="SampleRate">Sampling Rate</param>
/// <param name="df">Frequency interval</param>
/// <param name="Unit">Date Unit: V/Vrms/DBV</param>
/// <returns>Spectrum result</returns>
public static double[] FFTSpectrum(double[] Wave, int SampleRate, ref double df, DataUnit Unit)
{
MWNumericArray WaveMatlab = Wave;
MWArray WavePointMatlab = Wave.Length;
MWArray SampleRateMatlab = SampleRate;
MWArray UnitMatlab = (int)Unit;
MWArray[] FFTResult;
double[,] X2D, Y2D;
double[] Y;
DSPClass DSPTask = new DSPClass();
FFTResult = DSPTask.Spectrum(2, WaveMatlab, WavePointMatlab, SampleRateMatlab, UnitMatlab);
X2D = (double[, ])FFTResult[1].ToArray();
Y2D = (double[, ])FFTResult[0].ToArray();
Y = new double[Y2D.Length];
df = X2D[0, 0];
Buffer.BlockCopy(Y2D, 0, Y, 0, Y2D.Length * sizeof(double));
return(Y);
}
/// <summary>
/// Filter
/// </summary>
/// <param name="inputData">Input waform data</param>
/// <param name="mode">Folter design method</param>
/// <param name="type">Filter type</param>
/// <param name="fpass1">PassBand left frequency</param>
/// <param name="fstop1">StopBand left frequency</param>
/// <param name="fpass2">PassBand right frequency</param>
/// <param name="fstop2">StopBand right frequency</param>
/// <param name="fs">Samplerate</param>
/// <param name="rp">Passband ripple</param>
/// <param name="rs">Stopband attenuation</param>
/// <returns>Output waveform data</returns>
private static double[] Filter(double[] inputData, DesignMethod mode, FilterType type, double fpass1, double fstop1, double fpass2, double fstop2, double fs, double rp = 0.1, double rs = 50)
{
MWNumericArray waveMatlab = inputData;
MWNumericArray wpMatlab;
MWNumericArray wsMatlab;
MWNumericArray wnMatlab;
MWArray typeMatlab;
MWArray rpMatlab = rp;
MWArray rsMatlab = rs;
MWArray[] resultMatlab;
double[] fpassandFstop = new double[4];
double[] frange = new double[2];
double[,] result2D;
double[] result;
switch (type)
{
case FilterType.Highpass:
if (fpass1 > fstop1)
{
wpMatlab = fpass1 / (fs / 2);
wsMatlab = fstop1 / (fs / 2);
}
else
{
wpMatlab = fstop1 / (fs / 2);
wsMatlab = fpass1 / (fs / 2);
}
typeMatlab = "high";
if (mode == DesignMethod.InvChebyshev)
{
wnMatlab = wsMatlab;
}
else
{
wnMatlab = wpMatlab;
}
break;
case FilterType.Lowpass:
if (fpass1 < fstop1)
{
wpMatlab = fpass1 / (fs / 2);
wsMatlab = fstop1 / (fs / 2);
}
else
{
wpMatlab = fstop1 / (fs / 2);
wsMatlab = fpass1 / (fs / 2);
}
typeMatlab = "low";
if (mode == DesignMethod.InvChebyshev)
{
wnMatlab = wsMatlab;
}
else
{
wnMatlab = wpMatlab;
}
break;
case FilterType.Bandpass:
fpassandFstop[0] = fpass1 / (fs / 2);
fpassandFstop[1] = fstop1 / (fs / 2);
fpassandFstop[2] = fpass2 / (fs / 2);
fpassandFstop[3] = fstop2 / (fs / 2);
Array.Sort(fpassandFstop);
frange[0] = fpassandFstop[1];
frange[1] = fpassandFstop[2];
wpMatlab = frange;
frange[0] = fpassandFstop[0];
frange[1] = fpassandFstop[3];
wsMatlab = frange;
typeMatlab = "bandpass";
if (mode == DesignMethod.InvChebyshev)
{
wnMatlab = wsMatlab;
}
else
{
wnMatlab = wpMatlab;
}
break;
case FilterType.Bandstop:
default:
fpassandFstop[0] = fpass1 / (fs / 2);
fpassandFstop[1] = fstop1 / (fs / 2);
fpassandFstop[2] = fpass2 / (fs / 2);
fpassandFstop[3] = fstop2 / (fs / 2);
Array.Sort(fpassandFstop);
frange[0] = fpassandFstop[1];
frange[1] = fpassandFstop[2];
wpMatlab = frange;
frange[0] = fpassandFstop[0];
frange[1] = fpassandFstop[3];
wsMatlab = frange;
typeMatlab = "stop";
if (mode == DesignMethod.InvChebyshev)
{
wnMatlab = wpMatlab;
}
else
{
wnMatlab = wsMatlab;
}
break;
}
DSPClass dspTask = new DSPClass();
switch (mode)
{
case DesignMethod.Butterworth:
resultMatlab = dspTask.Butter(1, waveMatlab, wpMatlab, wsMatlab, rpMatlab, rsMatlab, typeMatlab);
break;
case DesignMethod.Elliptic:
resultMatlab = dspTask.Ellip(1, waveMatlab, wpMatlab, wsMatlab, wnMatlab, rpMatlab, rsMatlab, typeMatlab);
break;
case DesignMethod.InvChebyshev:
default:
resultMatlab = dspTask.Cheb2(1, waveMatlab, wpMatlab, wsMatlab, wnMatlab, rpMatlab, rsMatlab, typeMatlab);
break;
}
result2D = (double[, ])resultMatlab[0].ToArray();
result = new double[result2D.Length];
Buffer.BlockCopy(result2D, 0, result, 0, result2D.Length * sizeof(double));
return(result);
}
