public WWComplex Filter(WWComplex x)
{
mDelayX.Filter(x);
WWComplex y = WWComplex.Zero();
// Direct form 1 structure
// Discrete-time signal processing 3rd edition pp.417 figure 6.14
// まずフィードフォワードの計算。
// ディレイから取り出した値に係数bを掛ける。
for (int i = 0; i <= mH.NumerDegree(); ++i)
{
y = WWComplex.Add(y, WWComplex.Mul(mB[i], mDelayX.GetNth(i)));
}
// フィードバックの計算。
for (int i = 1; i <= mH.DenomDegree(); ++i)
{
y = WWComplex.Add(y, WWComplex.Mul(mA[i], mDelayY.GetNth(i - 1)));
}
mDelayY.Filter(y);
return(y);
}
public IIRFilterBlockComplex(ComplexRationalPolynomial p)
{
mH = p;
mDelayX = new DelayComplex(p.NumerDegree() + 1);
mDelayY = new DelayComplex(p.DenomDegree() + 1);
mB = new WWComplex[p.NumerDegree() + 1];
for (int i = 0; i < mB.Length; ++i)
{
mB[i] = p.N(i);
}
mA = new WWComplex[p.DenomDegree() + 1];
mA[0] = WWComplex.Unity();
for (int i = 1; i < mA.Length; ++i)
{
mA[i] = WWComplex.Minus(p.D(i));
}
}
public IIRFilterBlockReal128(ComplexRationalPolynomial p)
{
mH = p;
mMaxOrder = p.NumerDegree();
if (mMaxOrder < p.DenomDegree())
{
mMaxOrder = p.DenomDegree();
}
mV = new decimal[mMaxOrder + 1];
mB = new decimal[mMaxOrder + 1];
for (int i = 0; i < mB.Length; ++i)
{
mB[i] = (decimal)p.N(i).real;
}
mA = new decimal[mMaxOrder + 1];
mA[0] = 1;
for (int i = 1; i < mA.Length; ++i)
{
mA[i] = (decimal)(-p.D(i).real);
}
}