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 z = new Vector(0);
    Vector p = new Vector(0);
    Vector num = new Vector(0);
    Vector den = new Vector(0);
    Vector Response = new Vector(0);

    double[] WcArray = new double[1];
    int Order; //design a fifth order filter.

    Order = IIRFilters.EllipticOrder(new double[2] { 5.0/15, 6.0/15 }, 0.1, 40, TFilterType.ftLowPass, ref WcArray, false);  //design analog protype
    IIRFilters.EllipticFilter(Order, 0.1,40, WcArray, TFilterType.ftLowPass, false, num, den, TIirFrequencyTransform.ftStateSpaceAnalog);

    SignalUtils.FrequencyResponse(num, den, Response, 32, false, TSignalWindowType.wtRectangular, 0);

    Vector FreqFr = MtxExpr.Ramp(Response.Length, 0, 30*0.5 / Response.Length); //X axis
    TeeChart.DrawIt(FreqFr, Response, "Frequency response", false);
}