private ComplexFIR Create_FIR_COMPLEX(int size)
{
try
{
ComplexFIR p = new ComplexFIR();
p.coef = new ComplexF[size];
p.size = size;
p.cplx = true;
p.frq.lo = p.frq.hi = -1.0f;
return p;
}
catch (Exception ex)
{
ComplexFIR pr = new ComplexFIR();
Debug.Write(ex.ToString());
return pr;
}
}
private ComplexFIR Create_FIR_Bandpass_COMPLEX(float lofreq, float hifreq, float samplerate, int size)
{
ComplexFIR p = new ComplexFIR();
ComplexF[] h;
float[] w;
float fc, ff, midpoint;
int i, msize;
float pi = 3.14159265358928f;
float twopi = 2 * pi;
h = new ComplexF[size];
if ((lofreq < -(samplerate / 2.0)) || (hifreq > (samplerate / 2.0)) || (hifreq <= lofreq))
return p;
else if (size < 1)
return p;
else
{
msize = size - 1;
midpoint = (float)(0.5f * msize);
p = Create_FIR_COMPLEX(size);
p.frq.lo = lofreq;
p.frq.hi = hifreq;
h = p.coef;
w = new float[size];
w = makewindow(size, w);
lofreq /= samplerate;
hifreq /= samplerate;
fc = (float)((hifreq - lofreq) / 2.0f);
ff = (float)((lofreq + hifreq) * pi);
for (i = 0; i < size; i++)
{
float k = (float)i - midpoint;
float tmp, phs = ff * k;
if ((float)i != midpoint)
tmp = (float)((Math.Sin(twopi * k * fc) / (pi * k)) * w[i]);
else
tmp = (float)(2.0f * fc);
tmp *= 2.0f;
h[i].Re = (float)(tmp * Math.Cos(phs));
h[i].Im = (float)(tmp * Math.Sin(phs));
}
return p;
}
}
