Class Householder

mix-matrix.h:5–20

// Use like `Householder<double, 8>::inPlace(data)` - size must be ≥ 1
template<typename Sample, int size>
class Householder {
	static constexpr Sample multiplier{-2.0/size};
public:
	static void inPlace(Sample *arr) {
		double sum = 0;
		for (int i = 0; i < size; ++i) {
			sum += arr[i];
		}

		sum *= multiplier;
		
		for (int i = 0; i < size; ++i) {
			arr[i] += sum;
		}
	};
};

// Use like `Hadamard<double, 8>::inPlace(data)` - size must be a power of 2
template<typename Sample, int size>