refactor

almost complete. Need to doublecheck names for functions in *_serial.h

include/numerics/detail/matmul_serial.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#include <cstdint> //uint64_t
+#include <stdexcept> // std::runtime_error
+
+#include "../utils/vector.h"
+#include "../utils/matrix.h"
+
+namespace numerics::detail{
+
+// ---------------- Matrix * Matrix ----------------
+	template <typename T>
+	inline utils::Matrix<T> matmul_serial(const utils::Matrix<T>& A, const utils::Matrix<T>& B){
+		const uint64_t m = A.rows();
+		const uint64_t n = A.cols(); // also B.rows()
+		const uint64_t p = B.cols();
+		if(n != B.rows()){
+			throw std::runtime_error("matmul: dimension mismatch");
+		}
+		T tmp;
+		utils::Matrix<T> C(m, p, T{0});
+		for (uint64_t i = 0; i < m; ++i){
+			for (uint64_t j = 0; j < n; ++j){
+				tmp = A(i,j);
+				for (uint64_t k = 0; k < p; ++k){
+					C(i,k) += tmp * B(j,k);
+				}
+			}
+		}
+		return C;
+	}
+
+
+} // namespace numerics
+