public Basic_Material(double[] ABS, double[] Phase_Delay)
{
Abs = ABS;
PD = Phase_Delay;
for (int i = 0; i < ABS.Length; i++)
{
Ref[i] = 1 - ABS[i];
}
//Interpolate a transfer function... this will probably be clumsy at first...
double rt2 = Math.Sqrt(2);
List <double> f = new List <double>();
f.Add(0);
f.Add(31.25 * rt2);
for (int oct = 0; oct < 9; oct++)
{
f.Add(62.5 * Math.Pow(2, oct));
f.Add(rt2 * 62.5 * Math.Pow(2, oct));
}
f.Add(24000);
List <double> pr = new List <double>();
pr.Add(0);
pr.Add(Math.Sqrt(1 - Abs[0]));
for (int oct = 0; oct < 7; oct++)
{
pr.Add(Math.Sqrt(1 - Abs[oct]));
pr.Add(Math.Sqrt((2 - Abs[oct] - Abs[oct + 1]) / 2));
}
if (pr.Count < f.Count)
{
pr.Add(Math.Sqrt(1 - Abs[7])); //8k
}
if (pr.Count < f.Count)
{
pr.Add(Math.Sqrt((1 - Abs[7] + (1 - Abs[7])) / 2)); //10k
}
if (pr.Count < f.Count)
{
pr.Add(Math.Sqrt(1 - Abs[7])); //12k
}
if (pr.Count < f.Count)
{
pr.Add(Math.Sqrt(1 - Abs[7])); //16k
}
while (pr.Count < f.Count)
{
pr.Add(1 - Abs[7]);
}
Transfer_Function = MathNet.Numerics.Interpolation.Interpolation.CreateAkimaCubicSpline(f.ToArray(), pr.ToArray());
}
public void ISO9613_1_Spline(double Tk, double Pa, double Hr)
{
double[] freq = new double[1024];
double df = 22050 / 1024;
for (int i = 1; i < 1025; i++)
{
freq[i - 1] = df * i;
}
Spectrum = MathNet.Numerics.Interpolation.Interpolation.CreateAkimaCubicSpline(freq, ISO9613_1_attencoef(freq, Tk, Pa, Hr));
}
public static double[] Pressure_Interpolation(double[][] ETC, int SampleRate_IN, int SampleRate_Out, double Rho_C)
{
double[][] SPLetc = new double[8][];
double[] Total_E = new double[8];
double[] time = new double[ETC[0].Length];
double dtIn = 1.0f / SampleRate_IN;
double dtOut = 1.0f / SampleRate_Out;
for (int i = 1; i < time.Length; i++)
{
time[i] = (double)i / SampleRate_IN;
}
for (int oct = 0; oct < 8; oct++)
{
SPLetc[oct] = new double[ETC[0].Length];
for (int i = 0; i < time.Length; i++)
{
Total_E[oct] += ETC[oct][i];
if (ETC[oct][i] > 0)
{
SPLetc[oct][i] = Math.Log10(ETC[oct][i]);
}
else
{
SPLetc[oct][i] = Math.Log10(1E-12);
}
}
}
int NewLength = (int)Math.Ceiling((double)(SampleRate_Out * ETC[0].Length) / SampleRate_IN);
double[][] NewETC = new double[8][];
double[] NewTE = new double[8];
for (int oct = 0; oct < 8; oct++)
{
MathNet.Numerics.Interpolation.IInterpolationMethod CS = MathNet.Numerics.Interpolation.Interpolation.CreateAkimaCubicSpline(time, SPLetc[oct]);
NewETC[oct] = new double[NewLength];
for (int i = 0; i < NewLength; i++)
{
NewETC[oct][i] = Math.Pow(10, CS.Interpolate(i * dtOut));
NewTE[oct] += NewETC[oct][i];
}
for (int i = 0; i < NewLength; i++)
{
NewETC[oct][i] *= Total_E[oct] / NewTE[oct];
}
}
return(ETCToPTC(NewETC, (double)NewLength / SampleRate_Out, SampleRate_Out, SampleRate_Out, Rho_C));
}
public static void Initialize_filter_functions()
{
int n = 100;
double[] A = new double[n];
double[] ph = new double[n];
for (int i = 0; i < 100; i++)
{
ph[i] = Math.PI / 2 * i;
A[i] = 0.25 * (ph[i] - Math.Cos(ph[i])) / (Math.PI * 2);
}
RCos_Integral = MathNet.Numerics.Interpolation.Interpolation.CreateAkimaCubicSpline(A, ph);
}
public static double[] Magnitude_Filter(double[] Octave_pressure, int sample_frequency, int length_starttofinish, int threadid)
{
double rt2 = Math.Sqrt(2);
int spec_length = length_starttofinish / 2;
List <double> f = new List <double>();
f.Add(0);
f.Add(31.25 * rt2);
for (int oct = 0; oct < 9; oct++)
{
f.Add(62.5 * Math.Pow(2, oct));
f.Add(rt2 * 62.5 * Math.Pow(2, oct));
}
f.Add(sample_frequency / 2);
double[] output = new double[spec_length];
double[] samplep = new double[spec_length];
List <double> pr = new List <double>();
pr.Add(Octave_pressure[0]);
pr.Add(Octave_pressure[0]);
for (int oct = 0; oct < 7; oct++)
{
pr.Add(Octave_pressure[oct]);
pr.Add((Octave_pressure[oct] + Octave_pressure[oct + 1]) / 2);
}
if (pr.Count < f.Count)
{
pr.Add(Octave_pressure[7]); //8k
}
if (pr.Count < f.Count)
{
pr.Add(Octave_pressure[7]); //10k
}
if (pr.Count < f.Count)
{
pr.Add(Octave_pressure[7]); //12k
}
if (pr.Count < f.Count)
{
pr.Add(Octave_pressure[7]); //16k
}
while (pr.Count < f.Count)
{
pr.Add(Octave_pressure[7]);
}
MathNet.Numerics.Interpolation.IInterpolationMethod prm = MathNet.Numerics.Interpolation.Interpolation.CreateAkimaCubicSpline(f.ToArray(), pr.ToArray());
double[] p_i = new double[spec_length];
for (int j = 0; j < spec_length; j++)
{
double fr = (j + 1) * (sample_frequency / 2) / spec_length;
p_i[j] = prm.Interpolate(fr);// / (fr);
}
return(p_i);
}
