added operator() to change values

cpp/Tensor2.h

@@ -10,41 +10,45 @@
 
 namespace tensors {
 
-	/** Rank 2 Tensor */
+/** Rank 2 Tensor */
-	template<int N1, int N2>
+template<int N1, int N2>
-	class Tensor2 {
+class Tensor2 {
-	protected:
+protected:
-		Tensor1<N1> T[N2];
+	Tensor1<N1> T[N2];
 
-	public:
+public:
 
-		/** default constructor */
+	/** default constructor */
-		Tensor2() {
+	Tensor2() {
-		}
+	}
 
-		/* construct from data */
+	/* construct from data */
-		Tensor2(const double data[N2][N1]) {
+	Tensor2(const double data[N2][N1]) {
-			for (int j = 0; j < N2; j++)
+		for (int j = 0; j < N2; j++)
-				T[j] = Tensor1<N1> (data[j]);
+			T[j] = Tensor1<N1> (data[j]);
-		}
+	}
 
-		/** construct from expression */
+	/** construct from expression */
-		template<class A, char I, char J>
+	template<class A, char I, char J>
-		Tensor2(const Tensor2Expression<A, Index<N1, I> , Index<N2, J> >& a) {
+	Tensor2(const Tensor2Expression<A, Index<N1, I> , Index<N2, J> >& a) {
-			for (int j = 0; j < N2; j++)
+		for (int j = 0; j < N2; j++)
-				T[j] = a(j);
+			T[j] = a(j);
-		}
+	}
 
-		double operator()(int i, int j) const {
+	const double & operator()(int i, int j) const {
-			return T[j](i);
+		return T[j](i);
-		}
+	}
 
-		/** convert to expression */
+	double & operator()(int i, int j) {
-		template<char I, char J> Tensor2Expression<Tensor2, Index<N1, I> , Index<
+		return T[j](i);
-				N2, J> > operator()(Index<N1, I> i, Index<N2, J> j) const {
+	}
-			return Tensor2Expression<Tensor2, Index<N1, I> , Index<N2, J> > (*this);
+
-		}
+	/** convert to expression */
-	};
+	template<char I, char J> Tensor2Expression<Tensor2, Index<N1, I> , Index<
+			N2, J> > operator()(Index<N1, I> i, Index<N2, J> j) const {
+		return Tensor2Expression<Tensor2, Index<N1, I> , Index<N2, J> > (*this);
+	}
+};
 
 } // namespace tensors