public void ProcessSignalAtCutOffFrequencyTestTest()
{
const double fd = 100;
const double dt = 1 / fd;
const double f0 = 10;
const double eps = 3e-3;
const double A0 = sqrt_2;
var x0 = new SamplesDigitalSignal(dt, 1024, t => A0 * Cos(2 * PI * f0 * t));
var x0_power = x0.Power;
Assert.AreEqual(1, x0_power, eps);
var rc = new LowPassRC(f0, dt);
var y0 = rc.Process(x0);
var y0_power = y0.Power;
Assert.AreEqual(x0_power / 2, y0_power, eps);
}
public void ImpulseResponseTest()
{
const double fd = 100;
const double dt = 1 / fd;
const double f0 = 10;
var rc = new LowPassRC(f0, dt);
var a = rc.A;
var b = rc.B;
var a0 = a[0];
var a1 = a[1] / a0;
var b0 = b[0] / a0;
var b1 = b[1] / a0;
var expected_impulse_response = new List <double>
{
b0,
b0 * -a1 + b1,
b0 * -a1 * -a1 + b1 * -a1,
b0 * -a1 * -a1 * -a1 + b1 * -a1 * -a1,
b0 * -a1 * -a1 * -a1 * -a1 + b1 * -a1 * -a1 * -a1,
b0 * -a1 * -a1 * -a1 * -a1 * -a1 + b1 * -a1 * -a1 * -a1 * -a1,
};
var delta = new double[expected_impulse_response.Count];
delta[0] = 1;
var impulse_response = rc.Process(delta).ToArray();
const double eps = 1e-17;
CollectionAssert.AreEqual(expected_impulse_response, impulse_response, GetComparer(eps));
}
