worked on fir/iir filters

math/dsp/fir/Complex.h

@@ -181,8 +181,16 @@ private:
 	}
 
 	// https://dsp.stackexchange.com/questions/4693/fir-filter-gain
-	static void normalizeAC(std::vector<std::complex<float>>& kernel, const float freq) {
-		throw std::runtime_error("TODO");
+	static void normalizeAC(std::vector<std::complex<float>>& kernel, const float freq, const float sRate) {
+//		std::complex<float> sum;
+//		for (size_t i = 0; i < kernel.size(); ++i) {
+//			const float t = (float) i / sRate;
+//			const float v = std::sin(t*freq);
+
+//		}
+//		for (auto f : kernel) {sum += f * sin;}
+//		for (auto& f : kernel) {f /= sum;}
+		throw std::runtime_error("todo");
 	}
 
 	/** build a lowpass filter kernel */