> A non trivial amount of functionality needs reimplementation (flatten for instance)
True, however I think you'll find that flatten does things that you don't want. Much of the Expr code makes scalar assumptions that might not apply. I tried to generalize some of my work in matrix expressions into the file sympy/strategies/rl.py . This contains a set of generic functions for flattening, distribution, glomming together, removing identities and unpacking. They were designed to be very general and make minimal assumptions. - We do not have "standard correct way" to interface with functions like factor, symplify, had, get, atoms, etc, so it is hard to be sure that you have implemented everything Some of these things like simplify can call on _eval_simplify. Some of them you get from Basic. Some of them, you're correct, you don't have at all. What does it mean to factor vectors exactly? Fortunately, you also don't have things like as_numer_denom, which Exprs have but which make little sense on Vectors > But this way has been proven to work in matrix expressions and is also used in Pernici's tensor module, so I am not against it. In contrast the other way has proven to work in physics.quantum. They're both reasonable. On Tue, Jun 11, 2013 at 9:21 AM, Stefan Krastanov < krastanov.ste...@gmail.com> wrote: > This is also one of the ways to go forward. I personally dislike it > because: > > - A non trivial amount of functionality needs reimplementation > (flatten for instance) > - We do not have "standard correct way" to interface with functions > like factor, symplify, had, get, atoms, etc, so it is hard to be sure > that you have implemented everything > - As a personal preference, I actually like "garbage in - garbage out" > > But this way has been proven to work in matrix expressions and is also > used in Pernici's tensor module, so I am not against it. > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sympy+unsubscr...@googlegroups.com. > To post to this group, send email to sympy@googlegroups.com. > Visit this group at http://groups.google.com/group/sympy?hl=en-US. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy?hl=en-US. For more options, visit https://groups.google.com/groups/opt_out.
