private double GetExpBandAmplitude(
double depth,
Dictionary <int, double> sideBandAmplitudeCache,
int band)
{
if (sideBandAmplitudeCache.ContainsKey(band))
{
return(sideBandAmplitudeCache[band]);
}
double amplitude;
double argument = depth * Math.Log(10.0) / 20.0;
if (band == 0)
{
amplitude = Bessel.Bessi(
argument: argument,
order: 0,
cache: besselCache);
}
else if (Math.Abs(band) % 2 == 0)
{
//Even
double sign = (Math.Abs(band) / 2) % 2 == 1 ? -1.0 : 1.0;
amplitude = sign * Bessel.Bessi(
argument: argument,
order: Math.Abs(band),
cache: besselCache);
}
else
{
//Odd
double sign = ((Math.Abs(band) - 1) / 2) % 2 == 1 ? -1.0 : 1.0;
if (band > 0)
{
sign *= -1.0;
}
amplitude = sign * Bessel.Bessi(
argument: argument,
order: Math.Abs(band),
cache: besselCache);
}
sideBandAmplitudeCache[band] = amplitude;
return(amplitude);
}