X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=NEWS;h=934d6caa9392c747be30feb95379f8a3bd2ac448;hp=de39569dc4c5dfd387273bdbadb26a5212dc41c4;hb=197594750cb42582eb69c8690fea2221e3f72205;hpb=b1f684b10d31daafc4e4a5bdaee02ba455abe747 diff --git a/NEWS b/NEWS index de39569d..934d6caa 100644 --- a/NEWS +++ b/NEWS @@ -1,18 +1,21 @@ This file records noteworthy changes. -0.8.0 () +0.8.0 (24 March 2001) * Complete revamp of indexed objects. Instead of multiple classes for indexed things and their indices there is now only one "indexed" class 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.