On Mon, Jun 21, 2010 at 9:40 PM, Aaron S. Meurer <asmeu...@gmail.com> wrote:
>
> On Jun 21, 2010, at 10:31 PM, Ondrej Certik wrote:
>
>> Hi Christian,
>>
>> On Mon, Jun 21, 2010 at 8:24 PM, Christian Muise
>> <christian.mu...@gmail.com> wrote:
>>> I was asked to update the list with my progress daily until Friday, so I'll
>>> keep this quick.
>>> I've pushed hard against the branch to remove the old assumptions, and as
>>> of a few minutes ago I've managed to get the sympy/core working smooth:
>>> ======= tests finished: 329 passed, 6 expected to fail, in 12.57 seconds
>>> =======
>>> - Commit: 5e76a479db9f5ad2c55a
>>> This is in contrast with the state of affairs just after the discussion
>>> late last week:
>>> tests finished: 306 passed, 22 failed, 5 expected to fail,
>>> 1 expected to fail but passed, 1 exceptions, in 8.12 seconds
>>> - Commit: 91bcb155b24fd354cfdc
>>> And this is the stats on my netbook for the master branch (just in case
>>> those times looked a little high):
>>> ======= tests finished: 390 passed, 7 expected to fail, in 11.58 seconds
>>> =======
>>> Few things worth noting:
>>> - Most of the default assumption handling occurs now in the Expr class. It
>>> dispatches to the global_assumptions if there is a straight up assumption
>>> referring to the current query (<var>.is_foo), then attempts to
>>> _eval_is_foo, and in some cases check's related is_foo2's.
>>> - Instead of commenting out / deleting the tests that used assumptions, I
>>> rewrote them to use global assumptions. There may be more in the core that
>>> I've missed, but once they're stripped from the constructor those should
>>> surface. This flies against the recommended path, but I think they test
>>> important things and we can always place them some place else (it's easy to
>>> locate all instances in the testing files).
>>> - I found that from time to time an expression would be cached, and then the
>>> symbol would be used later with different assumptions. This proved to be
>>> /extremely/ problematic and hard to debug. Would it be worth modifying the
>>> cache so that all expressions related to a symbol (eg. x) are dumped when
>>> the Symbol('x') is called again?
>>
>> This is a phenomenal progress! Thanks for this. Yes, you have just
>> discovered another problem, why I so desperately want to get the old
>> assumptions gone --- caching. And exactly because of the bugs that you
>> posted, the cache has to be either fixed or removed.
>>
>> I would be more than happy if we can remove all caching altogether,
>> but since it currently would slow sympy down, Well, maybe not anymore.
>> We should do some tests. But let's say we need to keep the cache (at
>> least optional).
>>
>> Do I understand correctly, that now the expressions don't remember
>> their assumptions themselves, but you need to use either local or
>> global assumptions? If so, I would just store the pure expression in
>> the cache and only store the result in some form, that is independent
>> of the assumptions. Or maybe with the assumptions themselves -- e.g.
>> both an expression and the assumptions.
>>
>> Ondrej
>
> Aren't some results dependent on assumptions? I don't see how you can cache
> independent of assumptions and not have problems.
For example:
1) check that there are no global or local assumptions set
2) store the expression
retrieve:
* check 1)
* use cache
Ondrej
--
You received this message because you are subscribed to the Google Groups
"sympy" group.
To post to this group, send email to sy...@googlegroups.com.
To unsubscribe from this group, send email to
sympy+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/sympy?hl=en.
