Method getTransferFunction

src/ChowDSP.hpp:70–81

Computes the complex transfer function $H(s)$ at a particular frequency s: normalized angular frequency equal to $2 \pi f / f_{sr}$ ($\pi$ is the Nyquist frequency) */

	s: normalized angular frequency equal to $2 \pi f / f_{sr}$ ($\pi$ is the Nyquist frequency)
	*/
	std::complex<T> getTransferFunction(T s) {
		// Compute sum(a_k z^-k) / sum(b_k z^-k) where z = e^(i s)
		std::complex<T> bSum(b[0], 0);
		std::complex<T> aSum(1, 0);
		for (int i = 1; i < ORDER; i++) {
			T p = -i * s;
			std::complex<T> z(simd::cos(p), simd::sin(p));
			bSum += b[i] * z;
			aSum += a[i - 1] * z;
		}
		return bSum / aSum;
	}

	T getFrequencyResponse(T f) {
		return simd::abs(getTransferFunction(2 * M_PI * f));