public IIRFilter(IIRFilterType Type, int Order, float SampleRate)
{
m_filterType = Type;
m_order = Math.Min(16, Math.Max(1, Math.Abs(Order)));
m_sampleRate = SampleRate;
m_fN = 0.5f * m_sampleRate;
Design();
}
/// <summary>
/// Creates an instance of IIRFilter class
/// </summary>
/// <param name="a">A coefficients of the filter</param>
/// <param name="b">B coefficients of the filter</param>
/// <param name="type">Filter type</param>
public IIRFilter(double[] aCoefficients, double[] bCoefficients, IIRFilterType type)
{
if (null == aCoefficients)
{
throw new ArgumentNullException(nameof(aCoefficients));
}
FilterType = type;
numberCoefficients = aCoefficients.Length;
aCoef = aCoefficients;
bCoef = bCoefficients;
x = new double[numberCoefficients];
y = new double[numberCoefficients];
}
/// <summary>
/// Creates an instance of IIRFilter class
/// </summary>
/// <param name="type">Filter type</param>
/// <param name="order">Filter order</param>
/// <param name="cutoffFrequency">Filter cutoff frequency in radians per second</param>
/// <param name="samplingPeriod">Filter sampling period</param>
public IIRFilter(IIRFilterType type, int order, double cutoffFrequency, double samplingPeriod)
{
aCoef = new double[2];
bCoef = new double[2];
cuttoffFreqRadpS = cutoffFrequency;
FilterType = type;
switch (type)
{
case IIRFilterType.Butterworth:
ComputeButterworth(order, cutoffFrequency, samplingPeriod);
break;
default:
throw new NotImplementedException("Other filter types are not implemented yet.");
}
numberCoefficients = aCoef.Length;
x = new double[numberCoefficients];
y = new double[numberCoefficients];
}
