NAME

       tensor3 - a third order tensor

SYNOPSYS

       The  tensor3  class  defines  a  fourth  tensor where indices varie from zero to 2 (aka 3D
       physical space).

IMPLEMENTATION

       template<class T>
       class tensor3_basic {
       public:

         typedef size_t size_type;
         typedef T      element_type;
         typedef T      float_type;

       // allocators:

         tensor3_basic (const T& init_val = 0);
         tensor3_basic (const tensor3_basic<T>& a);

       // affectation:

         tensor3_basic<T>& operator= (const tensor3_basic<T>& a);
         tensor3_basic<T>& operator= (const T& val);

       // accessors:

         T&       operator()(size_type i, size_type j, size_type k);
         const T& operator()(size_type i, size_type j, size_type k) const;

       // algebra
         tensor3_basic<T>& operator*= (const T& k);
         tensor3_basic<T>& operator/= (const T& k) { return operator*= (1./k); }
         tensor3_basic<T>  operator*  (const T& k) const;
         tensor3_basic<T>  operator/  (const T& k) const;
         tensor_basic<T>   operator*  (const point_basic<T>& v) const;
         tensor3_basic<T>  operator*  (const tensor_basic<T>& b) const;
         tensor3_basic<T>  operator+  (const tensor3_basic<T>& b) const;
         tensor3_basic<T>  operator-  (const tensor3_basic<T>& b) const;

       // inputs/outputs:

         std::ostream& put (std::ostream& s, size_type d = 3) const;
         std::istream& get (std::istream&);

       // data:
       protected:
         T _x [3][3][3];
       };
       typedef tensor3_basic<Float> tensor3;