Refactor progress

Next step is ramdom and equal. I also need to have a look at add and the serial naming of the functions.

include/numerics/detail/mean_serial.h

@@ -0,0 +1,55 @@
+#pragma once
+
+#include <cstdint> //uint64_t
+//#include <stdexcept> // std::runtime_error
+
+#include "../utils/vector.h"
+#include "../utils/matrix.h"
+
+#include "sum_serial.h"
+
+namespace numerics::detail{
+	
+	// ---------------- Matrix -> Scalar ----------------
+	template <typename T>
+	T mean_serial(const utils::Matrix<T>& A) {
+	    const uint64_t rows = A.rows();
+	    const uint64_t cols = A.cols();
+		T sum = detail::sum_serial(A);
+		sum /= static_cast<T>(rows*cols);
+		return sum;
+	}
+
+	// ---------------- Vector -> Scalar ----------------
+	template <typename T>
+	T mean_serial(const utils::Vector<T>& v) {
+		const uint64_t N = v.size();
+		T sum = detail::sum_serial(v);
+		sum /= static_cast<T>(N);
+		return sum;
+	}
+
+	// ---------------- Matrix -> Vector ----------------
+	template <typename T>
+	utils::Vector<T> mean_rowwise_serial(const utils::Matrix<T>& A) {
+		const T cols = static_cast<T>(A.cols());
+		utils::Vector<T> sum = detail::sum_rowwise_serial(A);
+		const uint64_t N = sum.size();
+		for (uint64_t i = 0; i < N; ++i){
+			sum[i] /= cols;
+		}
+		return sum;
+	}
+
+	template <typename T>
+	utils::Vector<T> mean_colwise_serial(const utils::Matrix<T>& A) {
+		const T rows = static_cast<T>(A.rows());
+		utils::Vector<T> sum = detail::sum_colwise_serial(A);
+		const uint64_t N = sum.size();
+		for (uint64_t i = 0; i < N; ++i){
+			sum[i] /= rows;
+		}
+		return sum;
+	}
+} // namespace numerics
+