Re: [sympy] Re: GSOC Symbolic Classical Mechanics in SymPy

A project is never finished, so do not worry, there is always more work to do. However you should check our codebase in order to know what the status is. The `mechanics` module is, as I already said, mostly developed by the pydy organization. We can accept projects related to them if the projects a

Re: [sympy] Re: GSOC Symbolic Classical Mechanics in SymPy

Thanks a lot, Stefan. That was exactly the information I was looking for. The linearization and visualization projects look perfect. I'll get to work on an application immediately. Regards. On Thursday, May 2, 2013 1:47:00 PM UTC+5:30, Stefan Krastanov wrote: > > A project is never finished, s

[sympy] GSoC application for work under PyDy

Hello everyone, My name is Varun Joshi. I'm a Masters student in Mechanical Engineering at the Ohio State University where I work in the Movement Lab ( http://www.movement.osu.edu). I've been in touch with the PyDy group on their mailing list and since I will be applying to both groups for GSoC I

[sympy] Re: GSoC application for work under PyDy

Hi everyone, Regarding Pull request #2067, I guess the simplify() command works in different ways on different python versions. So my test works on python 2.7 but not on the other versions. That's rather strange. Could someone help me out with this? Varun Joshi On Thu, May 2, 2013 at 6:16 AM, V

Re: [sympy] GSoC application for work under PyDy

> I am interested specifically in the code generation idea under PyDy, i.e. > creating output codes which work directly with numerical ODE solvers, and > will definitely be visiting this group more often over the coming months to > get some guidance. In your proposal you would have to show not onl

Re: [sympy] GSoC application for work under PyDy

Thanks Stefan, I'll read up on the pre-existing routines. > Are you applying only to SymPy or also to the Python Foundation? If PyDy is part of an umbrella org be sure to apply to it. I am applying to both for sure. I just haven't made the other one public since they are both basically the same ap

Re: [sympy] controlling simplification

It may be late to reply on this topic. but i just want to add that all functionality of sympy works with evaluate=True on add/mul . If you are dealing with evaluate=False ,there are lots of chances that you will face max recursion errors or some unwanted results . I have faced similar issues while

Re: [sympy] Re: GSOC Symbolic Classical Mechanics in SymPy

Oh, I am sorry for the late reply. It seems Stefan has covered pretty much everything though. And, I am sorry if my post misled you. But then, other community members can always correct you :) -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubs

[sympy] Re: How to implement an DifferentialOperator that can do this kind calculation

The referred solution in Stackoverflow as showed to work really well. In my local SymPy version (which is a fork of 0.7.2-git from 30/04/2013) I've added an engineering module

[sympy] Re: Vector Calculus module

I had a 2 day break between exams so I began work on the CoordSystem class. Hopefully, I'll be able to make a WIP PR before 15th. One problem I am facing is this: In this class, there is a *lot* of initialization going on. A part of that is generating non-commutative symbols to represent the ba

[sympy] GSoC deadline coming up

Hi, Just a quick reminder, that the submission deadline is tomorrow at noon pacific time, which means: make yourself a deadline to submit today. And you'll be fine. Ondrej -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group

[sympy] Should __eq__ ever check for something more than structural equality?

I have found a few pieces of code where `__eq__` is extended to check for more than structural equality and this causes some routines to fail. Am I right to revert __eq__ to checking only for structural equality (and fixing related tests)? The code in question is `tensor.py` line 1318. -- You re

Re: [sympy] Should __eq__ ever check for something more than structural equality?

I remember being told to never override __eq__. In general I support this policy. I often implement .equals when I need more mathematical equality checking. Perhaps renaming __eq__ to .equals would be better than deletion. On Thu, May 2, 2013 at 2:39 PM, Stefan Krastanov wrote: > I have foun

[sympy] unify can not match functions?

`unify(sin(x), g(x), variables=[g])` returns an empty list (instead of `sin`). I am aware of the mess with `Function` and co. Is there a way around this? -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving

[sympy] Re: GSoC 2013: Univariate polynomials over algebraic domains

I was unsure how the two algorithms compare, this is why I didn't include the integer polynomial case in my proposal. But it would be great to also work on this case. -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and s

Re: [sympy] unify can not match functions?

If you're willing to work off of a development branch git remote add mrocklin g...@github.com:mrocklin/sympy.git git remote update mrocklin git checkout mrocklin/logpy-start bin/isympy In [1]: import sympy.logpy In [2]: from logpy.variables import variables In [3]: from logpy.unify import unify

Re: [sympy] unify can not match functions?

Ah, this also depends on development version of logpy, branch assoccomm-registry On Thu, May 2, 2013 at 3:52 PM, Matthew Rocklin wrote: > If you're willing to work off of a development branch > > git remote add mrocklin g...@github.com:mrocklin/sympy.git > git remote update mrocklin > git che

Re: [sympy] unify can not match functions?

Or just cherry pick this https://github.com/mrocklin/sympy/commit/c6b2ed058dbf16d577181360864dabd1e2f6029e On Thu, May 2, 2013 at 3:57 PM, Matthew Rocklin wrote: > Ah, this also depends on development version of logpy, branch > assoccomm-registry > > > > > On Thu, May 2, 2013 at 3:52 PM, Matthe

Re: [sympy] unify can not match functions?

Thanks a lot! On 2 May 2013 23:02, Matthew Rocklin wrote: > Or just cherry pick this > https://github.com/mrocklin/sympy/commit/c6b2ed058dbf16d577181360864dabd1e2f6029e > > > On Thu, May 2, 2013 at 3:57 PM, Matthew Rocklin wrote: >> >> Ah, this also depends on development version of logpy, branc

[sympy] GSoC deadlines

Just a reminder to all students that the deadline to submit your application in Melange is tomorrow (Friday) at 1900 UTC sharp. Google does not make exceptions to this rule. Get it in now, as there are usually network issues in Melange near the deadline (and Google generally does not extend the de

Re: [sympy] GSoC deadline coming up

Oh sorry, I didn't see this thread before I posted mine. Anyway, mine also mentioned the patch deadline, and it doesn't hurt to stress it more. Aaron Meurer On Thu, May 2, 2013 at 12:50 PM, Ondřej Čertík wrote: > Hi, > > Just a quick reminder, that the submission deadline is tomorrow at > noon p

Re: [sympy] Should __eq__ ever check for something more than structural equality?

This is very similar to the automatic evaluation question that comes up all the time. If you make things compare equal, then it becomes impossible to distinguish them. As such, you should reasonably expect any instance of one to be replaced with another by just about anything. A common way around

[sympy] Checking if a point is NOT a solution to a function

As part of a check to see if a function can be separated into a product of functions of its individual variables, I'm trying to implement an algorithm based on a theorem by Jose Angel Cid ( http://webs.uvigo.es/angelcid/Archivos/Papers/IJMEST.pdf) I need to select a point of (x,y) such that f(x,

[sympy] GSoC 2013 Idea - Find Domain / Range / Continuity / Singularity of a Function

Hi, Since I haven't formally introduced myself, I'm Paanini Navilekar, a final year student of Electrical Engineering at BITS-Pilani, Goa Campus in India. I've been using Python for small scripts and automation tasks around my computer, but I've never worked on a large-scale project before. Wh

Re: [sympy] Checking if a point is NOT a solution to a function

One could also use dummy symbols x0 and y0 with the implicit assumption that f(x0, y0) != 0. If you used this in solving an ODE, would they end up canceling out at the end? Aaron Meurer On Thu, May 2, 2013 at 6:25 PM, Paanini Navilekar wrote: > As part of a check to see if a function can be sep

Re: [sympy] Re: GSoC application for work under PyDy

I am quite swamped and only was briefly able to look at your pull request but I would advise not using or relying on simplify in tests if at all possible. For one, it is slow, and it alos gives different results depending on python versions, and finally, its implementation could easily change down

Re: [sympy] Re: GSoC application for work under PyDy

On Thu, May 2, 2013 at 8:09 PM, Dale Lukas Peterson wrote: > I am quite swamped and only was briefly able to look at your pull > request but I would advise not using or relying on simplify in tests > if at all possible. For one, it is slow, and it alos gives different > results depending on pytho

Re: [sympy] Re: GSoC application for work under PyDy

Hi Dale, The problem has been fixed, the function works and has passed all tests. I got some help from Stefan. It can still be improved though, so any comments would help. In the end this might not even go into the test file. I'm waiting for a reply on the PyDy group about where this code should

[sympy] Have 2 * log(2) written as log(4)

Not sure how to get this behavior in sympy - or even if it's possible. It doesn't just go for this particular example, I want to be able to do it for all such logs. Many thanks!!! Sympy rocks -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsu

Re: [sympy] Have 2 * log(2) written as log(4)

Unfortunately, log automatically pulls out powers like this. If you want, we could certainly discuss the merits of not having it do this. As a workaround, you can use log(4, evaluate=False). I think you could also subclass log and give it a custom eval that doesn't do that. Something like this se

Re: [sympy] Have 2 * log(2) written as log(4)

logs automatically simplify perfect powers. To create a log that doesn't do this you can use evaluate=False: >>> log(4,evaluate=False) log(4) To do this to an entire expression you can do >>> def logjoin(m): ... if not m.is_Mul: return m ... c, args = m.as_coeff_mul() ... if c is S.One: retur

Re: [sympy] Re: GSoC application for work under PyDy

> SymPy has a function called test_numerically in > sympy.utilities.randtest that can help with this approach. Cool, I wasn't aware of that. Good to know. Luke -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop r

Re: [sympy] GSoC 2013 Idea - Find Domain / Range / Continuity / Singularity of a Function

2. Finding all points of continuity in the function (if any), and checking if the function is continuous at a given point or a given interval. I think something you could use to do this is denoms: denoms(eq, symbols=None) Return (recursively) set of all denominators that appear in eq that

Re: [sympy] Have 2 * log(2) written as log(4)

That's fine - I understand the merits of pulling out the powers. I'm just looking to be able to rewrite things like 2 * log(2) as log(4) when I so desire. Thanks for your suggestions and I will play around with them! On Friday, 3 May 2013 13:40:29 UTC+10, Aaron Meurer wrote: > > Unfortunately, l

Re: [sympy] Have 2 * log(2) written as log(4)

That's fine - I understand the merits of pulling out the powers. I'm just looking to be able to rewrite things like 2 * log(2) as log(4) when I so desire. Thanks for your suggestions and I will play around with them! On Friday, 3 May 2013 13:40:29 UTC+10, Aaron Meurer wrote: > > Unfortunately, l

Re: [sympy] Have 2 * log(2) written as log(4)

Your second suggestion is perfect as it is exactly what I am looking to do - many thanks! You guys are so on the ball :- ) On Friday, 3 May 2013 13:49:23 UTC+10, smichr wrote: > > logs automatically simplify perfect powers. To create a log that doesn't > do this you can use evaluate=False: > > >

[sympy] Re: GSOC Application

Hi, I have added references about algorithms as well as added a new section "Demo" in my proposal. I know it's very near the deadline and I may be spamming. The proposal already had some reviews from Aaron Meurer and David Joyner. Just posting it notifying about the changes made in proposal. I am

Re: [sympy] Have 2 * log(2) written as log(4)

Actually, I don't understand the merits. Why do we do it? Your case gives a clear instance where it would not be desired. Doing so manually would not be hard (just expand_log). Aaron Meurer On Thu, May 2, 2013 at 10:04 PM, Ben Lucato wrote: > That's fine - I understand the merits of pulling out

Re: [sympy] Have 2 * log(2) written as log(4)

The perfect power of base was there before issue 1827 which I worked on...things would work via simplify if auto-simplification were not there >>> log(10)-log(2)-log(5) -log(5) - log(2) + log(10) >>> simplify(_) 0 >>> log(16,evaluate=False)-log(16) -4*log(2) + log(16) >>> simplify(_) 0 At least I

Re: [sympy] Should __eq__ ever check for something more than structural equality?

A problem with automatic canonicalization is that it would slow down the construction of big TensMul objects; constructing the product of ``n`` tensors would require ``n - 1`` canonicalizations instead of one. To avoid this, the automatic canonicalization is delayed to when TensMul objects are s