and two types of indices: "idx" for simple indices and "varidx" for
indices with variance. There are predefined delta, epsilon and metric
tensors, and a function simplify_indexed() that performs canonicalization
- and dummy index summations.
+ and dummy index summations. Matrix objects can be indexed for doing simple
+ linear algebra.
* Added an option "expand_indexed" to expand() to perform expansion of
indexed objects like (a+b).i -> a.i + b.i
* Renamed get_indices() to get_free_indices(), which no longer returns
dummy indices and checks the consistency of indices in sums.
* sqrfree() factorization fixed and improved syntactically.
* subs() works on matrices.
+* Matrices can be constructed from flat list of elements; diagonal matrices
+ can be constructed from list of diagonal elements with diag_matrix()
* Fixed memory leak in expand().
* Operator% for objects of class ncmul has gone. Use operator* now for that
case too, which is much more natural.