[LORENE] New class Tensor_sym

[Eric Gourgoulhon]

Dear All,

The new class Tensor_sym has been introduced to deal
with arbitrary valence tensors which are symmetric
with respect to two of their indices.
It has been motivated by the handling of tensor
symmetries in computing covariant derivatives.

Tensor_sym is a derived class of Tensor.
It is pretty similar to the old class Tenseur_sym
(derived class of Tenseur), except that the
two symmetric indices can be at arbitrary
positions: in old class Tenseur_sym, the
symmetric indices were necessary the last ones.

The class Sym_tensor is now a derived class of
Tensor_sym: it represents the special case of
valence 2.

The class Tensor_delta has been suppressed:
tensors with such properties are now simply
declared as Tensor_sym with valence 3.

Best wishes,

     Eric.


-- 
Eric Gourgoulhon
Laboratoire de l'Univers et de ses THeories (LUTH)
UMR 8102 du CNRS / Observatoire de Paris, F-92195 Meudon Cedex, France
tel: +33 1.45.07.74.33 (secretariat : +33 1.45.07.75.10)
e-mail: Eric.Gourgoulhon/at/obspm.fr    WWW: http://www.luth.obspm.fr/