Dan | 1 Sep 01:36 2010
Picon

Re: Help on solving a trig. equation

Aaron,

Many thanks for your clear explanations of the problem. Sympy is
awesome, you managed to get a result in the end, but I don't think
many users would have been able to get this one to work.

I'd be interested to know why it doesn't work straight off and why
your hack got a result.

--

-- 
You received this message because you are subscribed to the Google Groups "sympy" group.
To post to this group, send email to sympy@...
To unsubscribe from this group, send email to sympy+unsubscribe@...
For more options, visit this group at http://groups.google.com/group/sympy?hl=en.

Ondrej Certik | 1 Sep 02:21 2010
Picon

github: sympy pull requests

Hi,

github just introduced a nice review system:

http://github.com/blog/712-pull-requests-2-0

so I have just uploaded my first pull request:

http://github.com/sympy/sympy/pull/1

you can see all sympy pull requests here:

http://github.com/sympy/sympy/pulls

Let's see how it works. Here are our current "pull requests":

http://code.google.com/p/sympy/issues/list?q=label:NeedsReview

if you are an author of some of those patches, do you think you can
please upload your patch to github and create a pull request against
the sympy/sympy github repository? All people who have push access
should be notified, and it should appear in the pull request page.
That way we can test if it simplifies our workflow.

Ondrej

--

-- 
You received this message because you are subscribed to the Google Groups "sympy" group.
To post to this group, send email to sympy@...
To unsubscribe from this group, send email to sympy+unsubscribe@...
(Continue reading)

Aaron S. Meurer | 1 Sep 03:53 2010
Picon

Re: Re: Help on solving a trig. equation

It doesn't work because our solve() is a little poor at solving more complex equations like that one right
now.  To be honest, you will find with SymPy that it is really good at some things and not so good at others,
because everything is implemented by volunteers, who only implement things that they are interested in
or need for something.  The good news is that the list of things it is good at is always increasing and the list
of things that it is bad at is always shrinking, and it has gotten pretty good at many things in the past few
years.  

So basically, what I did should be implemented (recognize that it is a polynomial in some function of x, in
this case cos(x), then solve recursively), but it isn't.  If you are interested in improving the
algorithm, we are always welcome to contributions.  Just ask here or on the IRC channel if you need help.  

Aaron Meurer

On Aug 31, 2010, at 5:36 PM, Dan wrote:

> Aaron,
> 
> Many thanks for your clear explanations of the problem. Sympy is
> awesome, you managed to get a result in the end, but I don't think
> many users would have been able to get this one to work.
> 
> I'd be interested to know why it doesn't work straight off and why
> your hack got a result.

--

-- 
You received this message because you are subscribed to the Google Groups "sympy" group.
To post to this group, send email to sympy@...
To unsubscribe from this group, send email to sympy+unsubscribe <at> googlegroups.com.
For more options, visit this group at http://groups.google.com/group/sympy?hl=en.

(Continue reading)

Aaron S. Meurer | 1 Sep 04:01 2010
Picon

Re: github: sympy pull requests

This makes me realize that we should have some way to indicate who has the branch for review in a NeedsReview
issue (I have no idea which of those issues have a branch from me, without looking at each individually). 
Any ideas?  Maybe we could add the person's user name as a label.

Aaron Meurer

On Aug 31, 2010, at 6:21 PM, Ondrej Certik wrote:

> Hi,
> 
> github just introduced a nice review system:
> 
> http://github.com/blog/712-pull-requests-2-0
> 
> so I have just uploaded my first pull request:
> 
> http://github.com/sympy/sympy/pull/1
> 
> you can see all sympy pull requests here:
> 
> http://github.com/sympy/sympy/pulls
> 
> 
> Let's see how it works. Here are our current "pull requests":
> 
> http://code.google.com/p/sympy/issues/list?q=label:NeedsReview
> 
> if you are an author of some of those patches, do you think you can
> please upload your patch to github and create a pull request against
> the sympy/sympy github repository? All people who have push access
(Continue reading)

Ondrej Certik | 1 Sep 06:21 2010
Picon

Re: github: sympy pull requests

On Tue, Aug 31, 2010 at 7:01 PM, Aaron S. Meurer <asmeurer@...> wrote:
> This makes me realize that we should have some way to indicate who has the branch for review in a NeedsReview
issue (I have no idea which of those issues have a branch from me, without looking at each individually).
 Any ideas?  Maybe we could add the person's user name as a label.

I think that if we like github, we can move all the review over there.
There might still be some quirks, so we'll see.

Ondrej

--

-- 
You received this message because you are subscribed to the Google Groups "sympy" group.
To post to this group, send email to sympy@...
To unsubscribe from this group, send email to sympy+unsubscribe <at> googlegroups.com.
For more options, visit this group at http://groups.google.com/group/sympy?hl=en.

Aaron S. Meurer | 1 Sep 06:26 2010
Picon

Re: github: sympy pull requests

I am not saying that we should move our issue tracker to GitHub (I would be opposed to doing that unless there
were some way to import existing issues from Google Code, and even then only if it could be shown that it has
all the already existing features plus more to make it worth it).  

What I was saying is that there are 78 NeedsReview issues, and no way to tell which ones are ones that I have a
branch up for.  I think if we just add the person's user name as a label to an issue whenever they add a
patch/branch, it will make things easier (I would use Owner, but that is already used for other things, and
can only have one person at a time).

Unless there are any opposed to this idea, I will go ahead and do it.

Aaron Meurer

On Aug 31, 2010, at 10:21 PM, Ondrej Certik wrote:

> On Tue, Aug 31, 2010 at 7:01 PM, Aaron S. Meurer <asmeurer@...> wrote:
>> This makes me realize that we should have some way to indicate who has the branch for review in a
NeedsReview issue (I have no idea which of those issues have a branch from me, without looking at each
individually).  Any ideas?  Maybe we could add the person's user name as a label.
> 
> I think that if we like github, we can move all the review over there.
> There might still be some quirks, so we'll see.
> 
> Ondrej
> 

--

-- 
You received this message because you are subscribed to the Google Groups "sympy" group.
To post to this group, send email to sympy@...
To unsubscribe from this group, send email to sympy+unsubscribe <at> googlegroups.com.
(Continue reading)

Ondrej Certik | 1 Sep 06:54 2010
Picon

Re: github: sympy pull requests

On Tue, Aug 31, 2010 at 9:26 PM, Aaron S. Meurer <asmeurer@...> wrote:
> I am not saying that we should move our issue tracker to GitHub (I would be opposed to doing that unless there
were some way to import existing issues from Google Code, and even then only if it could be shown that it has
all the already existing features plus more to make it worth it).

I agree that we should keep the issues where they are. I meant that
maybe we can use github for code reviews instead of sympy-patches.

>
> What I was saying is that there are 78 NeedsReview issues, and no way to tell which ones are ones that I have a
branch up for.  I think if we just add the person's user name as a label to an issue whenever they add a
patch/branch, it will make things easier (I would use Owner, but that is already used for other things, and
can only have one person at a time).
>
> Unless there are any opposed to this idea, I will go ahead and do it.

Go ahead, that'd be awesome!

Ondrej

--

-- 
You received this message because you are subscribed to the Google Groups "sympy" group.
To post to this group, send email to sympy@...
To unsubscribe from this group, send email to sympy+unsubscribe <at> googlegroups.com.
For more options, visit this group at http://groups.google.com/group/sympy?hl=en.

Aaron S. Meurer | 1 Sep 22:18 2010
Picon

Re: github: sympy pull requests

On Aug 31, 2010, at 10:54 PM, Ondrej Certik wrote:

> On Tue, Aug 31, 2010 at 9:26 PM, Aaron S. Meurer <asmeurer@...> wrote:
>> I am not saying that we should move our issue tracker to GitHub (I would be opposed to doing that unless
there were some way to import existing issues from Google Code, and even then only if it could be shown that
it has all the already existing features plus more to make it worth it).
> 
> I agree that we should keep the issues where they are. I meant that
> maybe we can use github for code reviews instead of sympy-patches.

Oh, OK.  Yes, let's try it.

> 
>> 
>> What I was saying is that there are 78 NeedsReview issues, and no way to tell which ones are ones that I have a
branch up for.  I think if we just add the person's user name as a label to an issue whenever they add a
patch/branch, it will make things easier (I would use Owner, but that is already used for other things, and
can only have one person at a time).
>> 
>> Unless there are any opposed to this idea, I will go ahead and do it.
> 
> Go ahead, that'd be awesome!

OK.  So from now on, whenever an issue has the NeedsReview tag or the PassedReview tag, add the Google Code
username of the person who has the patch/branch for review to the issue.  It will warn you that you are using
an uncommon label, but that is just because I don't want to add everyone's username as an official label.  

Only problem:  for some people who are not members of the sympy Google Code project, their username appears
as an obfuscated email address.  What do you think we should do for these people?

(Continue reading)

Ondrej Certik | 1 Sep 22:48 2010
Picon

Re: github: sympy pull requests

On Wed, Sep 1, 2010 at 1:18 PM, Aaron S. Meurer <asmeurer@...> wrote:
> On Aug 31, 2010, at 10:54 PM, Ondrej Certik wrote:
>
>> On Tue, Aug 31, 2010 at 9:26 PM, Aaron S. Meurer <asmeurer@...> wrote:
>>> I am not saying that we should move our issue tracker to GitHub (I would be opposed to doing that unless
there were some way to import existing issues from Google Code, and even then only if it could be shown that
it has all the already existing features plus more to make it worth it).
>>
>> I agree that we should keep the issues where they are. I meant that
>> maybe we can use github for code reviews instead of sympy-patches.
>
> Oh, OK.  Yes, let's try it.

It's in, so now if you want to read the old revieew or comment on it
(or reopen it), go to:

http://github.com/sympy/sympy/pulls

and click "Closed", or just go here directly:

http://github.com/sympy/sympy/pull/1

Btw --- github automatically noticed, that I have pushed the patches
in using "git push" and it closed the pull request. I am getting
excited for this. :)

>
>>
>>>
>>> What I was saying is that there are 78 NeedsReview issues, and no way to tell which ones are ones that I have
(Continue reading)

Rahul Siddharthan | 2 Sep 15:48 2010
Picon

trigsimp bug? (Attempts to implement SICM)

Hello,
I am trying to re-implement most of the code from "Structure and
Interpretation of Classical Mechanics" (Sussman and Wisdom,
http://mitpress.mit.edu/sicm) in sympy.  The original language is
their particular dialect of Scheme.  I have had success with most of
the first chapter, but with quite a few "kludges": I will mail the
mailing list with details when the code is a bit cleaner.

Currently, I find the following issue:

theta = Function("theta")
phi = Function("phi")
psi = Function("psi")
t = symbols("t")
trigsimp(expand(diff(theta(t),
t)*sin(phi(t))*sin(psi(t))*sin(theta(t)),True,True),True,True)
(output)==>  0
trigsimp(expand(diff(theta(t),
t)*sin(phi(t))*sin(psi(t))*sin(theta(t)),True,True),True,False)
(output)==>  D(theta(t), t)*sin(phi(t))*sin(psi(t))*sin(theta(t))

The second answer is correct, the first is wrong.  Is there a problem
with recursive evaluation when derivatives are present?  I ran into
this problem when trying to simplify the derivative of a matrix.
Without "recursive", non-derivative expressions are rather
inadequately simplified; with "recursive", expressions containing
derivatives apparently return zero.

A previous issue, while I am on the subject: "from sympy import *"
clobbers the Python builtin "sum" function, so eg
(Continue reading)


Gmane