private static void Supertransform(double[] b, double[] a, double[] zb, double[] za, double fs)
{
int numOfCoeffs = b.Length;
int order = numOfCoeffs - 1;
double[] zplus1 = { 1.0f, 1.0f };
double[] zminus1 = { 1.0f, -1.0f };
double[][] polys = new double[numOfCoeffs][];
for (int i = 0; i < numOfCoeffs; i++)
{
polys[i] = Convolution.Conv(ArrayPower(zplus1, order - i), ArrayPower(zminus1, i));
}
for (int i = 0; i < numOfCoeffs; i++)
{
zb[i] = 0;
za[i] = 0;
for (int j = 0; j < numOfCoeffs; j++)
{
zb[i] += (double)(polys[j][i] * b[j] * Math.Pow(2 * fs, j));
za[i] += (double)(polys[j][i] * a[j] * Math.Pow(2 * fs, j));
}
}
}
//
/// <summary>
/// Calculates the power of a polynomial by convoluting its coefficients with it self n-times
/// </summary>
/// <param name="a">The coefficients of the polynomial</param>
/// <param name="n">The power to which to raise the polynomial</param>
/// <returns>The resulting polynomial coefficients after raising the poly to power-of-n</returns>
public static double[] ArrayPower(double[] a, int n)
{
double[] output = { 1f };
for (int i = 0; i < n; i++)
{
output = Convolution.Conv(output, a);
}
return(output);
}
/**
* Process an incoming signal with the defined impulse response
* @param input Input signal to be processed
* @return processed signal <b>without</b> the "tail". output.length = input.length
*/
public double[] Process(double[] input)
{
double[] data = Convolution.Conv(this.response, input);
double[] output = new double[input.Length];
double[] newTail = new double[tail.Length];
int i = 0;
while (i < data.Length)
{
if (i < output.Length)
{
// Ef data liggur á bilinu 0...output length, færa gögn í output
output[i] = data[i];
if (i < tail.Length)
{
output[i] += tail[i];
}
}
else
{
// Ef data liggur út fyrir output þá færa restina í nýtt tail
newTail[i - output.Length] = data[i];
if (i < tail.Length) // Ef það er eitthvað eftir af gamla teilinu bæta því við
{
newTail[i - output.Length] += tail[i];
}
}
i++;
}
this.tail = newTail;
return(output);
}
