[sage-support] Re: intersection points of circles - irritating
fixed at http://trac.sagemath.org/sage_trac/ticket/8487 R.M. On 9 bře, 05:26, Markus markus_la...@gmx.net wrote: Hi, when trying to compute the intersection points of 2 circles i got strange results. Example 1: c1(x,y)=(x-5)^2+y^2-25; c2(x,y)=(y-3)^2+x^2-9 solve([c1(x,y)==0,c2(x,y)==0],x,y) produces the expected result: [[x == (45/17), y == (75/17)], [x == 0, y == 0]] Example 2: (circle 1 smaller) c1(x,y)=(x-5)^2+y^2-16; c2(x,y)=(y-3)^2+x^2-9 solve([c1(x,y)==0,c2(x,y)==0],x,y) produces the unexpected result: [] whereas intersection points do exist, e.g. x=(-9(sqrt(55)-15)/68, y=(-3(sqrt(55)-41)/68 Is it because Example 1 has a rational result, whereas Examples 2 has an irrational one? Thanks for any help. Markus -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] clifford algebras etc.
Hi, I am currently trying to switch from commercial CAS to sage. As a physicist I need to handle non-commutative algebras, most notably Clifford algebras. I have read that GiNaC is pretty good in that and that sage is using a variant called Pynac. Does Pynac have the non-commutative algebras which are extensively used in theoretical high energy physics: Clifford algebras, SU(3) Lie algebras, and Lorentz tensors. (quotes from the Wikipaedia article on GiNaC) ? -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] Re: Xelatex and Sage notebook
Hi, is already http://trac.sagemath.org/sage_trac/ticket/8472 R.M. On 10 bře, 08:51, Kwankyu ekwan...@gmail.com wrote: Hi Dan, I worked on this. Would you review Trac 8486? http://trac.sagemath.org/sage_trac/ticket/8486 Thank you in advance. Kwankyu -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] Can I factor x^2 - 2 and get (x-sqrt(2))*(x+sqrt(2)) ?
Hi, A friend of mine wants to factorize symbolicly x^2 - 2 : sage: p = x^2 - 2 sage: p.factor() x^2 - 2 Apparently p.roots() gives almost what he wants : sage: p.roots() [(-sqrt(2), 1), (sqrt(2), 1)] So, I just proposed him to do : sage: Factorization([(x-r,m) for r,m in p.roots()]) (x - sqrt(2)) * (x + sqrt(2)) Do any of you have a better solution? Thank you, Sébastien Labbé, Montpellier -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] Symmetric group: bug with trivial cycle
Hello,
I get a strange error while constructing permutation from a cycle
decomposition. Is it a bug or not the right way to build a
permutation ?
{{{
sage: G = SymmetricGroup(3)
sage: G([(2,3), (1,)])
(2,3)
sage: G([(1,), (2,3)])
---
TypeError Traceback (most recent call
last)
[...]
TypeError: Gap produced error output
Syntax error: ; expected
$sage8:=(1)(2, 3);;
^
executing $sage8:=(1)(2, 3);;
}}}
(the same error occurs by using the constructor
PermutationGroupElement instead of G)
Vincent
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[sage-support] 3D plot in sage
Hi everyone,I want do this thing as follows in sage, is that
OK?var('x,y,z')f=cos(x)*cos(y)+cos(y)*cos(z)+cos(z)*cos(x)and then I want to
plot f. how can do it in sage?Thanks in advance!regards,YC
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[sage-support] Re: 3D plot in sage
On Mar 10, 9:39 am, wxu...@sohu.com wrote:
Hi everyone,I want do this thing as follows in sage, is that
OK?var('x,y,z')f=cos(x)*cos(y)+cos(y)*cos(z)+cos(z)*cos(x)and then I want to
plot f. how can do it in sage?Thanks in advance!regards,YC
Isn't this a 4d plot? Or do you want to plot f(x,y,z)=0? In that
case, you could do
sage: implicit_plot3d(f == 0, (x, -2, 2), (y, -2, 2), (z, -2, 2))
--
John
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[sage-support] Re: Can I factor x^2 - 2 and get (x-sqrt(2))*(x+sqrt(2)) ?
On Mar 10, 3:23 am, slabbe sla...@gmail.com wrote: Hi, A friend of mine wants to factorize symbolicly x^2 - 2 : sage: p = x^2 - 2 sage: p.factor() x^2 - 2 Apparently p.roots() gives almost what he wants : sage: p.roots() [(-sqrt(2), 1), (sqrt(2), 1)] Or sage: p.roots(multiplicities=False) [-sqrt(2), sqrt(2)] So, I just proposed him to do : sage: Factorization([(x-r,m) for r,m in p.roots()]) (x - sqrt(2)) * (x + sqrt(2)) Do any of you have a better solution? How about: sage: S.y = PolynomialRing(QQ[sqrt(2)]) sage: p = y^2 - 2 sage: p.factor() (y - sqrt2) * (y + sqrt2) (I don't know why it says sqrt2 instead of sqrt(2).) -- John -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
Re: [sage-support] Re: Can I factor x^2 - 2 and get (x-sqrt(2))*(x+sqrt(2)) ?
On Mar 10, 2010, at 10:15 AM, John H Palmieri wrote: On Mar 10, 3:23 am, slabbe sla...@gmail.com wrote: Hi, A friend of mine wants to factorize symbolicly x^2 - 2 : sage: p = x^2 - 2 sage: p.factor() x^2 - 2 Apparently p.roots() gives almost what he wants : sage: p.roots() [(-sqrt(2), 1), (sqrt(2), 1)] Or sage: p.roots(multiplicities=False) [-sqrt(2), sqrt(2)] So, I just proposed him to do : sage: Factorization([(x-r,m) for r,m in p.roots()]) (x - sqrt(2)) * (x + sqrt(2)) Do any of you have a better solution? How about: sage: S.y = PolynomialRing(QQ[sqrt(2)]) sage: p = y^2 - 2 sage: p.factor() (y - sqrt2) * (y + sqrt2) (I don't know why it says sqrt2 instead of sqrt(2).) That is because this is a number field, and generator names are supposed to be atomic. - Robert -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] saving data from interact
Hello all, I am using a sage notebook interact to generate and display some random graphs (more specifically a self-created extension of the graph class with extra properties) and would like to have the chance to save the output. Usually the notebook makes all defined variables global and I can specifically save certain results, but since I have defined my interact as a function all of the objects created seem to be local and disappear when the interact is finished. (other than for the graph output) I have tried to pickle the objects and save to a file but sage doesn't seem to allow me to pickle self defined classes. I was wondering if there was a standard way that people work around this. Thank you in advance for your help, sage is a wonderful piece of software. David Monarres -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
Re: [sage-support] saving data from interact
On Wed, Mar 10, 2010 at 11:17 AM, D. Monarres dmmonar...@gmail.com wrote: Hello all, I am using a sage notebook interact to generate and display some random graphs (more specifically a self-created extension of the graph class with extra properties) and would like to have the chance to save the output. Usually the notebook makes all defined variables global and I can specifically save certain results, but since I have defined my interact as a function all of the objects created seem to be local and disappear when the interact is finished. (other than for the graph output) I have tried to pickle the objects and save to a file but sage doesn't seem to allow me to pickle self defined classes. I was wondering if there was a standard way that people work around this. Thank you in advance for your help, sage is a wonderful piece of software. David Monarres This is easy. Just use the global keyword in Python.Here's an example: http://sagenb.org/home/pub/1757/ William -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] plot3d in notebook generates no plot
Hi all,
I just installed Sage and now I'm working through the tutorial.
However, inside notebook I'm unable to generate 3d plots: Issuing i.e.
x,y = var('x,y')
plot3d(x^2 + y^2, (x,-2,2), (y,-2,2))
only yields a gray square without any plots. At the right lower corner
of the square there is a link Get Image, but clicking on it do not get
the image but jumps the top of the current worksheet (the address of the
link is http://localhost:8000/home/admin/3/#;).
On the Sage command line plot3d works, a Jmol window pops up showing the
graphic. Also inside notebook plot3d(..., viewer='tachyon') works.
Java (OpenJDK) is installed and enabled in the browser.
In this group, there was a thread
http://groups.google.com/group/sage-support/browse_thread/thread/150340666982775/ad08c6a84218c53f?lnk=gstq=plot3d+notebook#ad08c6a84218c53f
describing the same issue, but without giving any solution.
My system:
Dell Optiplex GX620, Intel Pentium 630, 1GB RAM
:~$ uname -a
Linux Adler 2.6.24-27-generic #1 SMP Mon Feb 22 18:17:28 UTC 2010 x86_64
GNU/Linux
:~$ lsb_release -d
Description:Ubuntu 8.04.4 LTS
:~$ sage --version
| Sage Version 4.3.3, Release Date: 2010-02-21 |
installed tar ball:
sage-4.3.3-linux-64bit-ubuntu_8.04.4_lts-x86_64-Linux.tar.gz
:~$ java -version
java version 1.6.0_0
OpenJDK Runtime Environment (build 1.6.0_0-b11)
OpenJDK 64-Bit Server VM (build 1.6.0_0-b11, mixed mode)
:~$ firefox --version
Mozilla Firefox 3.0.18, Copyright (c) 1998 - 2010 mozilla.org
Any help is appreciated. Thanks in advance
Eckhard
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[sage-support] Re: saving data from interact
Thank you very much, that was a great help. Is there a way to pickle user defined types? So that I can, say, email my advisor files containing the sage objects. On Mar 10, 11:25 am, William Stein wst...@gmail.com wrote: On Wed, Mar 10, 2010 at 11:17 AM, D. Monarres dmmonar...@gmail.com wrote: Hello all, I am using a sage notebook interact to generate and display some random graphs (more specifically a self-created extension of the graph class with extra properties) and would like to have the chance to save the output. Usually the notebook makes all defined variables global and I can specifically save certain results, but since I have defined my interact as a function all of the objects created seem to be local and disappear when the interact is finished. (other than for the graph output) I have tried to pickle the objects and save to a file but sage doesn't seem to allow me to pickle self defined classes. I was wondering if there was a standard way that people work around this. Thank you in advance for your help, sage is a wonderful piece of software. David Monarres This is easy. Just use the global keyword in Python. Here's an example: http://sagenb.org/home/pub/1757/ William -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group athttp://groups.google.com/group/sage-support URL:http://www.sagemath.org -- William Stein Associate Professor of Mathematics University of Washingtonhttp://wstein.org -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
Re: [sage-support] plot3d in notebook generates no plot
On Mar 10, 2010, at 11:53 AM, Eckhard Kosin wrote:
Hi all,
I just installed Sage and now I'm working through the tutorial.
However, inside notebook I'm unable to generate 3d plots: Issuing i.e.
x,y = var('x,y')
plot3d(x^2 + y^2, (x,-2,2), (y,-2,2))
only yields a gray square without any plots. At the right lower
corner
of the square there is a link Get Image, but clicking on it do not
get
the image but jumps the top of the current worksheet (the address of
the
link is http://localhost:8000/home/admin/3/#;).
On the Sage command line plot3d works, a Jmol window pops up showing
the
graphic. Also inside notebook plot3d(..., viewer='tachyon') works.
Java (OpenJDK) is installed and enabled in the browser.
Do the demos at http://jmol.sourceforge.net/demo/ work for you?
- Robert
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[sage-support] Typesetting bug
There is a surprising typesetting bug in the sage 4.3.3 notebook interface, as it is running on sagenb.org, for example. If the Typset checkbox is ticked and one evaluates something like 6.5/x one gets 1/x So any floating point number is convered to 1 when it is divided by a symbolic variable. When the Typeset checkbox is unchecked, the correct 6.50/x is returned. To reproduce this, just open a worksheet and check the Typeset box and enter 6.5/x or take a look at http://www.sagenb.org/home/pub/1758 -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] Re: Typesetting bug
On Mar 10, 9:27 pm, Gustav Delius gustav.del...@gmail.com wrote: There is a surprising typesetting bug ... http://trac.sagemath.org/sage_trac/ticket/8491 -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
Re: [sage-support] Re: Typesetting bug
On Wed, 10 Mar 2010 12:35:28 -0800 (PST) Harald Schilly harald.schi...@gmail.com wrote: On Mar 10, 9:27 pm, Gustav Delius gustav.del...@gmail.com wrote: There is a surprising typesetting bug ... http://trac.sagemath.org/sage_trac/ticket/8491 Indeed this is very embarrassing. I can't believe I missed this, or it wasn't caught by any doctest. The cause is the broken py_numer() function in sage/symbolic/pynac.pyx. I will post a patch shortly. Thanks. Burcin -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] Re: bug in Sage's interface to Singular?
Hi all: It looks like working with polynomial rings over transcendental field extensions still doesn't work in Sage. Am i doing something wrong below? The same computation works in Singular, giving the correct answer of the ideal generated by x*y. Should i submit a Trac ticket for this? It appears someone has taken a look at the issue since i last reported it, because this time there's a new error. Alex -- | Sage Version 4.3.3, Release Date: 2010-02-21 | | Type notebook() for the GUI, and license() for information.| -- The Sage install tree may have moved. Regenerating Python.pyo and .pyc files that hardcode the install PATH (please wait at most a few minutes)... Do not interrupt this. sage: R0.q = PolynomialRing(QQ); R0 Univariate Polynomial Ring in q over Rational Field sage: k= FractionField(R0); k Fraction Field of Univariate Polynomial Ring in q over Rational Field sage: R.x,y = PolynomialRing(k); R Multivariate Polynomial Ring in x, y over Fraction Field of Univariate Polynomial Ring in q over Rational Field sage: I = R.ideal((q*x*y)^2); I Ideal (q^2*x^2*y^2) of Multivariate Polynomial Ring in x, y over Fraction Field of Univariate Polynomial Ring in q over Rational Field sage: I.radical() --- TypeError Traceback (most recent call last) /Users/arai021/ipython console in module() /Applications/sage/local/lib/python2.6/site-packages/sage/rings/ polynomial/multi_polynomial_ideal.py in __call__(self, *args, **kwds) 405 if not R.base_ring().is_field(): 406 raise ValueError(Coefficient ring must be a field for function '%s'.%(self.f.__name__)) -- 407 return self.f(self._instance, *args, **kwds) 408 409 require_field = RequireField /Applications/sage/local/lib/python2.6/site-packages/sage/rings/ polynomial/multi_polynomial_ideal.py in wrapper(*args, **kwds) 367 368 with RedSBContext(): -- 369 return func(*args, **kwds) 370 371 from sage.misc.sageinspect import sage_getsource /Applications/sage/local/lib/python2.6/site-packages/sage/rings/ polynomial/multi_polynomial_ideal.py in radical(self) 1397 import sage.libs.singular 1398 radical = sage.libs.singular.ff.primdec__lib.radical - 1399 r = radical(self) 1400 1401 S = self.ring() /Applications/sage/local/lib/python2.6/site-packages/sage/libs/ singular/function.so in sage.libs.singular.function.SingularFunction.__call__ (sage/libs/ singular/function.cpp:9628)() TypeError: Cannot call Singular function 'radical' with ring parameter of type 'class 'sage.rings.polynomial.multi_polynomial_ring.MPolynomialRing_polydict_domain'' On Jan 15, 2:58 pm, Alex Raichev tortoise.s...@gmail.com wrote: Hi all: I'm trying to get Sage to compute in a multivariate polynomial ring over a transcendental field extension but am running into difficulties. For example, Sage crashes when trying to compute a radical ideal as demonstrated by the example below. I tried the same example in Singular, which gave me the correct answer (the ideal generated by x*y). So is the failure below a Singular interface bug or am i doing something wrong? I suspect Singular doesn't like Sage's fraction field construction of a transcendental extension. Alex -- | Sage Version 4.3, Release Date: 2009-12-24 | | Type notebook() for the GUI, and license() for information. | -- WARNING: There is one major unsolved bug in some versions of Sage on OS X 10.6 that causes an 'Abort trap' crash when doing certain symbolic computations. Seehttp://trac.sagemath.org/sage_trac/ticket/7095/. sage: R0.q = PolynomialRing(QQ); R0 Univariate Polynomial Ring in q over Rational Field sage: k= FractionField(R0); k Fraction Field of Univariate Polynomial Ring in q over Rational Field sage: R.x,y = PolynomialRing(k); R Multivariate Polynomial Ring in x, y over Fraction Field of Univariate Polynomial Ring in q over Rational Field sage: R.x,y = PolynomialRing(k); R Multivariate Polynomial Ring in x, y over Fraction Field of Univariate Polynomial Ring in q over Rational Field sage: I = R.ideal((q*x*y)^2); I Ideal (q^2*x^2*y^2) of Multivariate Polynomial Ring in x, y over Fraction Field of Univariate Polynomial Ring in q over Rational Field sage: I.radical() --- RuntimeError Traceback (most recent call last) /Users/arai021/ipython console in module()
[sage-support] can't factor a symbolic expression with Laplace transforms
Hello,
I'm trying to factor a symbolic expression with Laplace transforms in
it:
sage: var('s t')
(s, t)
sage: y = function('y', t)
sage: lt = laplace(diff(y, t,t) - 3*diff(y, t) + 2*y , t, s)
sage: lt
s^2*laplace(y(t), t, s) - 3*s*laplace(y(t), t, s) - s*y(0) +
2*laplace(y(t), t, s) + 3*y(0) - D[0](y)(0)
sage: lt.factor()
[boom]
It ultimately complains about IndexError: tuple index out of range.
I'd like to see something like
laplace(y(t), t, s)*(s^2 - 3*s + 2) + 3*y(0) - D[0](y)(0)
and to hopefully get solve() to solve for laplace(y(t), t, s). Is this
possible?
Dan
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