/// <summary>
/// 频域修正
/// </summary>
/// <param name="data1"></param>
/// <param name="begin1"></param>
/// <param name="end1"></param>
/// <param name="data2"></param>
/// <param name="begin2"></param>
/// <param name="end2"></param>
/// <returns></returns>
public static int[] MiddleFilterCorrection(int[] data1, int begin1, int end1, int[] data2, int begin2, int end2)
{
int[] res = new int[end1 - begin1];
int k = Math.Max(end1 - begin1, end2 - begin2);
int dx = FToneAnalysis.getmin2x(k);
//double dl = (double)NNAnalysis.samplingRate / dx;
double[] fftdata1 = new double[dx];
double[] fftdataimag1 = new double[dx];
Array.Copy(data1, begin1, fftdata1, 0, Math.Min(k, end1 - begin1));
TWFFT.FFT(fftdata1, fftdataimag1);
double[] fftdata2 = new double[dx];
double[] fftdataimag2 = new double[dx];
Array.Copy(data2, begin2, fftdata2, 0, Math.Min(k, end2 - begin2));
TWFFT.FFT(fftdata2, fftdataimag2);
int num = 15;
double[] lineori1 = new double[dx];
double[] lineori2 = new double[dx];
for (int i = 0; i < dx; i++)
{
lineori1[i] = Math.Abs(fftdata1[i]);
lineori2[i] = Math.Abs(fftdata2[i]);
//lineori1[i] = Math.Sqrt(Math.Pow(fftdata1[i], 2) + Math.Pow(fftdataimag1[i], 2));
//lineori2[i] = Math.Sqrt(Math.Pow(fftdata2[i], 2) + Math.Pow(fftdataimag2[i], 2));
}
double[] line1 = FToneAnalysis.MiddleFilter(lineori1, num);
//double[] linei1 = FToneAnalysis.MiddleFilter(fftdataimag1, num);
double[] line2 = FToneAnalysis.MiddleFilter(lineori2, num);
//double[] linei2 = FToneAnalysis.MiddleFilter(fftdataimag2, num);
for (int i = 0; i < line1.Length; i++)
{
//Complex c1 = new Complex(fftdata1[i], fftdataimag1[i]);
//Complex cl1 = new Complex(line1[i], linei1[i]);
//Complex cl2 = new Complex(line2[i], linei2[i]);
//c1 = c1.Multiply(cl1.Division(cl2));
fftdata1[i] = (int)((double)fftdata1[i] * (line2[i] / line1[i]));
//fftdataimag1[i] += (int)(linei2[i]-linei1[i]);
}
for (int i = dx / 4; i < dx / 2; i++)
{
if (line2[i] < line1[i])
{
fftdata1[i] = fftdata2[i];
fftdata1[dx - i] = fftdata2[dx - i];
}
}
TWFFT.IFFT(fftdata1, fftdataimag1);
for (int i = 0; i < res.Length; i++)
{
res[i] = (int)fftdata1[i];
}
return(res);
}
/// <summary>
/// 用倒谱获得频谱包络
/// </summary>
/// <param name="data"></param>
/// <returns></returns>
private static double[] GetEnvelopeFD(double[] data)
{
int n = data.Length;
double[] data1 = new double[n];
double[] data1i = new double[n];
for (int i = 0; i < n; i++)
{
data1[i] = Math.Log(data[i]);
}
for (int i = 0; i < n; i++)
{
data1i[i] = 0;
}
TWFFT.FFT(data1, data1i);
double therehold = 100;
double[] data2 = new double[n];
double[] data2i = new double[n];
// 低通滤波
for (int i = 0; i < n; i++)
{
if (i < therehold || i > n - therehold)
{
data2[i] = data1[i];
data2i[i] = data1i[i];
}
else
{
data2[i] = 0;
data2i[i] = 0;
}
}
//for (int i = 0; i < n; i++) data2i[i] = 0;
TWFFT.IFFT(data2, data2i);
var res = FToneAnalysis.MiddleFilter(data2, 5);
for (int i = 0; i < n; i++)
{
res[i] = Math.Pow(Math.E, res[i]);
}
return(res);
}
