IIRFilters.BesselFilter Method (integer, array of TSample, TFilterType, boolean, TMtx, TVec, TVec, TSample)

The resulting transfer function is returned in the state-space form with A,B,C,D variables.

public double BesselFilter(int Order, double[] CutoffFreq, TFilterType FilterType, bool Analog, TMtx A, TVec B, TVec C, ref double d);

C# Example

Design a fifth order analog lowpass filter with the cutoff frequency at 3 rad/sec.

using Dew.Math;
using Dew.Math.Editors;
using Dew.Math.Units;
using Dew.Signal;
using Dew.Signal.Units;
using Dew.Math.Tee;
using Dew.Signal.Tee;

private void button1_Click(object sender, EventArgs e)
{
    Vector num = new Vector(0);
    Vector den = new Vector(0);
    Vector Response = new Vector(0);
    Vector FreqFr = new Vector(0);

    IIRFilters.BesselFilter(5, new double[1] {3}, TFilterType.ftLowPass, true, num,den,TIirFrequencyTransform.ftStateSpaceAnalog);  //design analog protype
    FreqFr.Length = 1000;
    SignalUtils.LogRamp(FreqFr, -1, 1);
    SignalUtils.FrequencyResponseS(num, den, FreqFr, Response, 0);
    TeeChart.DrawIt(Response, "Frequency response", false);
}