On Sat, May 23, 2009 at 11:14 PM, smichr wrote:
>
>
>
> On May 23, 10:08 pm, Abderrahim Kitouni wrote:
>>
>> > Can anyone tell me why in one context something appears to be a symbol
>> > but in another it doesn't? See the following:
>>
>> It seems you're just not getting how python works.
>>
>
On May 23, 10:08 pm, Abderrahim Kitouni wrote:
>
> > Can anyone tell me why in one context something appears to be a symbol
> > but in another it doesn't? See the following:
>
> It seems you're just not getting how python works.
>
Thanks for the reminder. I do understand, but not that I'm work
This is a problem. I have tried to send many patches through git, but
they are not showing up in http://groups.google.com/group/sympy-
patches/. I also resent the shebang line patch a long time ago as
Ondrej requested, but it isn't there either. Is the list moderated?
According to the g
On May 23, 2009, at 6:51 PM, Ondrej Certik wrote:
>
> by default? Or should we add some assumptions to "f", like "has
> continuous first derivatives".
>
> Thanks,
> Ondrej
That would definitely be a cool assumption to have. Note, that it
needs to have continuous second partials, not first. See
Hi Kenji!
On Wed, May 20, 2009 at 1:40 AM, kenji wrote:
>
> Hi all,
>
> I want to reresent Ricci tensors with metric tensors and their drivatives.
Yes, that'd be cool to have. If you get it working, definitely report
here, I am interested in that.
> So, I try to use sympy for partial different
On Fri, May 22, 2009 at 10:06 AM, Luke wrote:
>
> I would like to add code that would allow for diff() to differentiate
> with respect to not just Symbol instances, but also with respect to
> Function and Derivative instances. An example of why this would be
> useful would be when forming Lagran
On Sat, May 23, 2009 at 9:37 AM, Aaron S. Meurer wrote:
>
> Is there a way to determine if a function is a declared function such
> as f = Function('f'), but not a SymPy function such as sin. They both
> seem to have the same relevant attributes.
> >>> f(x,y).is_Atom
> False
> >>> f(x,y).is_Sy
Hi Chris,
On Sat, May 23, 2009 at 1:52 AM, smichr wrote:
>
>
>
> On May 23, 1:26 am, Ryan Krauss wrote:
>> I have an expression I can't seem to get to simplify to my liking (this is
>> my first real attemp to do simplification in SymPy):
>>
>> In [72]: x2a
>> Out[72]: (F1 + Gc*x1 + Gc*xd + k*x1
On Sat, May 23, 2009 at 5:19 PM, Ondrej Certik wrote:
> On Wed, May 20, 2009 at 11:58 AM, Robert Kern wrote:
>>
>> On Wed, May 20, 2009 at 13:55, Ondrej Certik wrote:
>>>
>>> Hi Pablo!
>>>
>>> On Wed, May 20, 2009 at 4:40 AM, Pablo W. wrote:
Hello,
I have been using sympy a
On Sat, May 23, 2009 at 2:40 PM, Luke wrote:
>
> It seems there is a bug:
> [matlab]
>>> integrand = 2*X*X + 2*Y*Y - 1
> integrand =
> 2*X^2+2*Y^2-1
>>> res = int(integrand, Y, -sqrt(1-X*X), sqrt(1-X*X))
> res =
> 4*X^2*(1-X^2)^(1/2)+4/3*(1-X^2)^(3/2)-2*(1-X^2)^(1/2)
>>> subs(res, X, 1)
> ans =
>
On Wed, May 20, 2009 at 11:58 AM, Robert Kern wrote:
>
> On Wed, May 20, 2009 at 13:55, Ondrej Certik wrote:
>>
>> Hi Pablo!
>>
>> On Wed, May 20, 2009 at 4:40 AM, Pablo W. wrote:
>>>
>>> Hello,
>>>
>>> I have been using sympy a lot recently (economical modelling) and
>>> (while it's a great so
Cool. I had created my own exec method similar to yours, but that feels
hackish. This is much better.
On Sat, May 23, 2009 at 2:06 PM, smichr wrote:
>
>
>
> On May 23, 9:28 pm, Ryan Krauss wrote:
> > Thanks Chris. That is both helpful and instructive.
> >
> > RYan
> >
>
> GTH.
>
> Say, I not
It seems there is a bug:
[matlab]
>> integrand = 2*X*X + 2*Y*Y - 1
integrand =
2*X^2+2*Y^2-1
>> res = int(integrand, Y, -sqrt(1-X*X), sqrt(1-X*X))
res =
4*X^2*(1-X^2)^(1/2)+4/3*(1-X^2)^(3/2)-2*(1-X^2)^(1/2)
>> subs(res, X, 1)
ans =
0
>> subs(res, X, 2)
ans =
0. +17.3205i
>>
[/matlab]
This is cool, it is good to see other people who are familiar with
Kane's method, there aren't many of us :)
Are you familiar with Autolev? With PyDy, I am working to achieve
some of the same behavior as Autolev, but make it even better, and
have a lot more features. I'd love to hear your input
In the solvers routines above nsolve there is a note:
# TODO: option for calculating J numerically
Can someone explain the rational for falling back to numerical
derivatives when the analytical forms are available through diff()? Is
it a matter of speed? I'm asking because I've worked on a routi
On May 23, 9:28 pm, Ryan Krauss wrote:
> Thanks Chris. That is both helpful and instructive.
>
> RYan
>
GTH.
Say, I noticed afterwards in the FAQ wiki that there is also an easier
way to create the variables you need. Given an expression like yours,
I could have (with the Symbols definition
On Sat, May 23, 2009 at 10:08 AM, Abderrahim Kitouni
wrote:
>
> Hi,
>
> On Sat, 23 May 2009 04:36:11 -0700 (PDT)
> smichr wrote:
>>
>> Can anyone tell me why in one context something appears to be a symbol
>> but in another it doesn't? See the following:
> It seems you're just not getting how p
Hi,
On Sat, 23 May 2009 04:36:11 -0700 (PDT)
smichr wrote:
>
> Can anyone tell me why in one context something appears to be a symbol
> but in another it doesn't? See the following:
It seems you're just not getting how python works.
>
> >>> a,b,c
> (a, b, c)
here a, b, c are symbols
> >>> eq=
Is there a way to determine if a function is a declared function such
as f = Function('f'), but not a SymPy function such as sin. They both
seem to have the same relevant attributes.
>>> f(x,y).is_Atom
False
>>> f(x,y).is_Symbol
False
>>> f(x,y).is_Function
True
>>> sin(x).is_Atom
False
Thanks Chris. That is both helpful and instructive.
RYan
On Sat, May 23, 2009 at 3:52 AM, smichr wrote:
>
>
>
> On May 23, 1:26 am, Ryan Krauss wrote:
> > I have an expression I can't seem to get to simplify to my liking (this
> is
> > my first real attemp to do simplification in SymPy):
> >
that is a bad news :(
I have thought to use py+sympy in my research work, but think I'd
better turn to matlab now.
On May 23, 2:57 am, Luke wrote:
> I get a slightly different result when integrating in Matlab (2008a):
> [matlab]
>
> >> syms X Y L H K;
> >> int(int(2*X*X+2*Y*Y-1, Y, -sqrt(1-X*X)
I made a small script in MuPAD few years ago but I had to say goodbye
to MuPAD last November, so I found Sympy and have translated it into
Sympy now. I want to share it and I'm happy if I get some comments.
What I made is the small script that generates motion equations for
multibody dynamics by
As an addendum to the above I see that there is more going on than
meets the eye:
>>> c=Symbol('c')
>>> id(c)
45184256
>>> c=1/c
>>> id(_)
68674260
So is my access to the first c lost in terms of namespace? i.e. when I
say 'c' now I am getting c#68674260 and will never get c#45184256?
--~--~---
Can anyone tell me why in one context something appears to be a symbol
but in another it doesn't? See the following:
>>> a,b,c
(a, b, c)
>>> eq=a+b
>>> b=c+3
>>> eq.atoms()
set([a, b])
>>> for s in _:
... print s
... assert s.is_Symbol
...
a
b
They both pass but...
>>> a.is_Symbol
Tru
(1) I wonder if a better name for div would be divmod to be consistent
with the mathematical function with the same behavior which gives both
the integer and remainder part of a division. div sounds a lot like
the "div" operator which just does division with a single result,
right?
(2) Also, I ra
On May 23, 1:26 am, Ryan Krauss wrote:
> I have an expression I can't seem to get to simplify to my liking (this is
> my first real attemp to do simplification in SymPy):
>
> In [72]: x2a
> Out[72]: (F1 + Gc*x1 + Gc*xd + k*x1)/(Gc + k)
>
[cut]
>
> Do I need to tell sympy something about Gc and
26 matches
Mail list logo
