Started Loss, done softmax, up to p.125

I've implemented alot of support functions that needs to be refactored, optimised and tested; mean.h, exponential.h, matdiv.h matsum.h matsubtract.h. Maybe we need to have a look at if matdiv/matmul should be in the same. Same with matadd/matsubtract and if some of it should be in matvec.h.

include/numerics/exponential.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include <cmath>
+
+#include "./utils/vector.h"
+#include "./utils/matrix.h"
+
+
+namespace numerics{
+	
+	template <typename T>
+	T exponential(const T a){
+		return std::exp(a);
+	}
+
+	template <typename T>
+	utils::Vector<T>  exponential(const utils::Vector<T>& a){
+		utils::Vector<T> b = a;
+		for (uint64_t i = 0; i < a.size(); ++i){
+			b[i] =  numerics::exponential(a[i]);
+		}
+		return b;
+	}
+
+	template <typename T>
+	utils::Matrix<T>  exponential(const utils::Matrix<T>& A){
+		utils::Matrix<T> B = A;
+		for (uint64_t i = 0; i < A.rows(); ++i){
+			for (uint64_t j = 0; j < A.cols(); ++j){
+				B(i,j) = numerics::exponential(A(i,j));
+			}
+		}
+		return B;
+	}
+
+
+
+} // namespace numerics
+