Apparently the setup.py is dated:
cjmu...@haz:~/Projects/sympy$ git diff
diff --git a/setup.py b/setup.py
index bdec104..538904d 100755
--- a/setup.py
+++ b/setup.py
@@ -71,6 +71,7 @@
'sympy.mpmath.matrices',
'sympy.mpmath.calculus',
'sympy.polys',
+ 'sympy.polys.domains',
'sympy.printing',
'sympy.printing.pretty',
'sympy.series',
cjmu...@haz:~/Projects/sympy$
On Thu, Aug 19, 2010 at 12:39 PM, Christian Muise <christian.mu...@gmail.com
> wrote:
> I'm having issues with the branch:
>
> >>> from sympy import *
> Traceback (most recent call last):
> File "<input>", line 1, in <module>
> File "/usr/local/lib/python2.6/dist-packages/sympy/__init__.py", line 24,
> in <module>
> from polys import *
> File "/usr/local/lib/python2.6/dist-packages/sympy/polys/__init__.py",
> line 3, in <module>
> from polytools import (
> File "/usr/local/lib/python2.6/dist-packages/sympy/polys/polytools.py",
> line 66, in <module>
> from sympy.polys.domains import FF, QQ
> ImportError: No module named domains
> >>>
>
> I guess it's the version I'm using? Python 2.6.5 is installed.
>
> On Wed, Aug 18, 2010 at 11:43 PM, Aaron S. Meurer <asmeu...@gmail.com>wrote:
>
>> So a few words. First, if you just pass it a strictly rational function,
>> it is nothing new. It will return the exact same result as integrate()
>> because it uses the exact same function, which is the already existing
>> ratint() (however, there is a fix in my branch for rational functions with
>> symbolic coefficients that fail in master).
>>
>> To really test this, you need to pass it a function that has exp and/or
>> log in it. For example, here are some functions that you might try that
>> better test the algorithm:
>>
>> In [2]: risch_integrate(1/(exp(x)**9 + 1), x)
>> Out[2]:
>> ⎛ 9⋅x⎞
>> log⎝1 + ℯ ⎠
>> x - ─────────────
>> 9
>>
>> (your example with x replaced with exp(x))
>>
>> In [18]: risch_integrate(diff(exp(x)*log(x)/(x + 1), x), x)
>> Out[18]:
>> x
>> ℯ ⋅log(x)
>> ─────────
>> 1 + x
>>
>> This seems to be a simple example, but observe that our current
>> integrate() cannot handle it:
>>
>> In [19]: integrate(diff(exp(x)*log(x)/(x + 1), x), x)
>> Out[19]:
>> ⌠
>> ⎮ ⎛ x x x ⎞
>> ⎮ ⎜ℯ ⋅log(x) ℯ ⋅log(x) ℯ ⎟
>> ⎮ ⎜───────── - ───────── + ─────────⎟ dx
>> ⎮ ⎜ 1 + x 2 x⋅(1 + x)⎟
>> ⎮ ⎝ (1 + x) ⎠
>> ⌡
>>
>> Also, it's fun to pass it functions that you know do not have elementary
>> anti-derivatives, to see if it can verify that fact:
>>
>> In [20]: risch_integrate(exp(x**2), x)
>> Out[20]:
>> ⌠
>> ⎮ ⎛ 2⎞
>> ⎮ ⎝x ⎠
>> ⎮ ℯ dx
>> ⌡
>>
>> In [21]: risch_integrate(1/log(x), x)
>> Out[21]:
>> ⌠
>> ⎮ 1
>> ⎮ ────── dx
>> ⎮ log(x)
>> ⌡
>>
>> Also, remember what I said about integrating random functions. If you try
>> to integrate a random function, the chances are pretty good that it will not
>> be elementary, and even if it is, the result could be quite complicated and
>> it could take a long time to compute. Much better is to come up with an
>> expression that is as complex or not complex as you like, then differentiate
>> it and see if risch_integrate() can give you the original thing back again.
>>
>> On Aug 18, 2010, at 9:05 PM, Ondrej Certik wrote:
>>
>> > Hi Aaron!
>> >
>> > On Thu, Aug 5, 2010 at 2:01 PM, Aaron S. Meurer <asmeu...@gmail.com>
>> wrote:
>> >> (copied from issue 2010)
>> >>
>> >> I have ready in my integration3 branch a prototype risch_integrate()
>> function, that is a user-level function for the full Risch Algorithm I have
>> been implementing this summer. Pull from
>> http://github.com/asmeurer/sympy/tree/integration3
>> >
>> > This is just excellent!
>> >
>> > I would like to invite everyone to try this. (Read Aaron's email above
>> > for things to try and not to try yet.) So here are some tougher cases:
>> >
>> > In [1]: risch_integrate(1/(x**8+1), x)
>> > [hangs]
>>
>> This is our old friend expand() again (if you break anything that hangs in
>> sympy these days, it usually ends up being in expand in the traceback). I
>> am hoping that Mateusz's continual Poly improvements will make this go away
>> eventually.
>>
>> >
>> >
>> > In [4]: cancel(risch_integrate(1/(x**9+1), x).diff(x))
>> > Out[4]:
>> > d ⎛ ⎛ 6 3 ⎞⎞ 3 d
>> ⎛
>> > 1 + 3⋅──⎝RootSum⎝531441⋅t + 729⋅t + 1, Λ(t, t⋅log(x + 9⋅t))⎠⎠ + 3⋅x
>> ⋅──⎝Root
>> > dx dx
>> >
>> ──────────────────────────────────────────────────────────────────────────────
>> > 3
>> > 3 + 3⋅x
>> >
>> > ⎛ 6 3 ⎞⎞
>> > Sum⎝531441⋅t + 729⋅t + 1, Λ(t, t⋅log(x + 9⋅t))⎠⎠
>> >
>> > ──────────────────────────────────────────────────
>> >
>> >
>> > It should be equivalent but it's a bit messy. Maybe we need to
>> > implement some symbolic manipulation of RootSum().
>>
>> Mateusz should look at this.
>>
>> >
>> > In [18]: risch_integrate(sqrt(1+exp(x)), x)
>> > NotImplementedError: Couldn't find an elementary transcendental
>> > extension for (1 + exp(x))**(1/2). Try using a manual extension with
>> > the extension flag.
>>
>> No, and it won't be any time soon. The algorithm I am implementing is
>> only the transcendental case (no algebraic functions like sqrt). Now, the
>> algebraic part does exist, but it is much more difficult to implement, and I
>> won't even start to do it until the transcendental case is finished. If you
>> get the above error, and you believe that the function is really not
>> algebraic, please post it here because it could be a bug in my preparser
>> algorithm, (be aware that you could be wrong, though).
>>
>> >
>> >
>> > [18] is probably not supported yet.
>> >
>> >
>> > Otherwise it works great. I wasn't able to make it break.
>>
>> Well, I know it's possible, because I do it all the time (and then I go
>> and fix the bug).
>>
>> >
>> >
>> > Ondrej
>>
>> Aaron Meurer
>>
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