[sage-support] var() function behavior changes when calculus.py is imported
When from sage.calculus.calculus import * is executed, the default
var() function from sage.calculus.var (L4) gets replaced by another
one from sage.symbolic.ring (L506).
There is indeed an import made in sage.calculus.calculus (L370).
However, the behavior of var() changes afterward because when var('n')
is called, the symbolic variable n is not automatically created.
So the following lines are valid before, but not after calling from
sage.calculus.calculus import *:
sage: var('n')
sage: n
Is this normal or should a ticket be opened ?
Cheers,
JP
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[sage-support] Re: any python plot3d ?
Its not well documented, unfortunately. I learned about from another developer (Jason Grout, I think). The patch creating it went in a while ago: http://trac.sagemath.org/sage_trac/ticket/6447 and I think they intended to add better documentation but no one did. In the next year or so hopefully there will be more work on using html5 and other recent browser improvements to do better 3d graphics (webgl for instance). -Marshall On Jan 17, 6:33 pm, kkwweett joel.d...@gmail.com wrote: thanks Marshall, I tried viewer option but this is not working for me (firefox,ubuntu) even if it is already better than a yellow warning. I used example from video3 ofhttp://www.sagemath.org/help-video.html def f(x,y): return sin(x-y)*y*cos(x) plot3d(f(x,y),(x-3,3),(y,-3,3)) but all I see is a blue flat grid (I can move it with the mouse though) How did you know about the viewer option ? I can't see it in the manual. -- 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: var() function behavior changes when calculus.py is imported
More explicitly:
sage: var('y')
y
sage: type(y)
type 'sage.symbolic.expression.Expression'
sage: from sage.calculus.calculus import *
sage: var('z')
z
sage: type(z)
---
snip
NameError: name 'z' is not defined
Huh. Can I ask where one would import * from sage.calculus.calculus?
Though I also don't think this is good.
Also, one sees various imports of this. I feel like messing with this
is asking for trouble, but there are a lot of different things done
here.
calculus/all.py:16:from var import (var, function, clear_vars)
functions/piecewise.py:83:from sage.calculus.all import var
symbolic/ring.pyx:766:sage: from sage.symbolic.ring import var
tensor/coordinate_patch.py:46:from sage.symbolic.ring import SR, var
tensor/differential_forms.py:46:from sage.symbolic.ring import SR, var
calculus/calculus.py:370:from sage.symbolic.ring import var, SR,
is_SymbolicVariable
calculus/desolvers.py:1187:from sage.calculus.var import var
calculus/desolvers.py:1493:from sage.symbolic.ring import
var
calculus/predefined.py:1:from sage.symbolic.ring import var as _var
On Jan 18, 4:59 am, Jean-Pierre Flori jpfl...@gmail.com wrote:
When from sage.calculus.calculus import * is executed, the default
var() function from sage.calculus.var (L4) gets replaced by another
one from sage.symbolic.ring (L506).
There is indeed an import made in sage.calculus.calculus (L370).
However, the behavior of var() changes afterward because when var('n')
is called, the symbolic variable n is not automatically created.
So the following lines are valid before, but not after calling from
sage.calculus.calculus import *:
sage: var('n')
sage: n
Is this normal or should a ticket be opened ?
Cheers,
JP
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[sage-support] Re: Errors When Starting Sage-4.6.1
I have no real idea what is going wrong there - I've never used Gentoo
and I suspect it must be something to do with its infrastructure. But
one idea would be to retry with gcc 4.5.2; my impression is that there
are some significant improvements between the 4.4 and 4.5 series.
You might also want to repost this on sage-devel, since there might be
some Gentoo users who read that and not sage-support.
-M. Hampton
On Jan 17, 8:36 pm, Richard richj...@pacbell.net wrote:
After compiling sage-4.6.1 (again), without errors in install.log, I try
to start up sage and get the following:
/usr/local/sage-4.6.1]$ ./sage
--
| Sage Version 4.6.1, Release Date: 2011-01-11 |
| Type notebook() for the GUI, and license() for information. |
--
ERROR: An unexpected error occurred while tokenizing input
The following traceback may be corrupted or invalid
The error message is: ('EOF in multi-line statement', (1097, 0))
ERROR: An unexpected error occurred while tokenizing input
The following traceback may be corrupted or invalid
The error message is: ('EOF in multi-line statement', (1102, 0))
---
TypeError Traceback (most recent call last)
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/IPython/ipmaker.pyc
in force_import(modname)
64 reload(sys.modules[modname])
65 else:
--- 66 __import__(modname)
67
68
/usr/local/sage-4.6.1/local/bin/ipy_profile_sage.py in module()
5 preparser(True)
6
7 import sage.all_cmdline
8 sage.all_cmdline._init_cmdline(globals())
9
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/all_cmdline.py
in module()
12 try:
13
--- 14 from sage.all import *
15 from sage.calculus.predefined import x
16 preparser(on=True)
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/all.py in
module()
70 get_sigs()
71
--- 72 from sage.rings.all import *
73 from sage.matrix.all import *
74
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/rings/all.py in
module()
91
92 # Algebraic numbers
--- 93 from qqbar import (AlgebraicRealField, is_AlgebraicRealField, AA,
94 AlgebraicReal, is_AlgebraicReal,
95 AlgebraicField, is_AlgebraicField, QQbar,
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/rings/qqbar.py
in module()
4220 return isinstance(x, AlgebraicNumber)
4221
- 4222 QQbarPoly = PolynomialRing(QQbar, 'x')
4223 AAPoly = PolynomialRing(AA, 'x')
4224
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/rings/polynomial/polynomial_ring_constructor.pyc
in PolynomialRing(base_ring, arg1, arg2, sparse, order, names, name,
implementation)
341 raise TypeError, if second arguments is a
string with no commas, then there must be no other non-optional arguments
342 name = arg1
-- 343 R = _single_variate(base_ring, name, sparse,
implementation)
344 else:
345 # 2-4. PolynomialRing(base_ring, names,
order='degrevlex'):
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/rings/polynomial/polynomial_ring_constructor.pyc
in _single_variate(base_ring, name, sparse, implementation)
421
422 elif base_ring.is_field(proof = False):
-- 423 R = m.PolynomialRing_field(base_ring, name, sparse,
implementation=implementation)
424
425 elif base_ring.is_integral_domain(proof = False):
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/rings/polynomial/polynomial_ring.pyc
in __init__(self, base_ring, name, sparse, element_class, implementation)
1252 element_class =
polynomial_element_generic.Polynomial_generic_dense_field
1253
- 1254 PolynomialRing_integral_domain.__init__(self, base_ring,
name=name, sparse=sparse, element_class=element_class)
1255
1256 self._has_singular = can_convert_to_singular(self)
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/rings/polynomial/polynomial_ring.pyc
in __init__(self, base_ring, name, sparse, implementation, element_class)
1187 raise ValueError, Unknown implementation %s
for ZZ[x]
1188 PolynomialRing_commutative.__init__(self, base_ring,
name=name,
- 1189 sparse=sparse, element_class=element_class)
1190
1191 def _repr_(self):
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/rings/polynomial/polynomial_ring.pyc
in __init__(self, base_ring, name, sparse, element_class)
1121 raise TypeError, Base
[sage-support] Re: var() function behavior changes when calculus.py is imported
Hi, Huh. Can I ask where one would import * from sage.calculus.calculus? In my badly written code. I wanted to call symbolic_sum which is not reachable by default, rather than sum when doing some tests. Cheers, JP -- 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: var() function behavior changes when calculus.py is imported
On Jan 18, 11:03 am, Jean-Pierre Flori jpfl...@gmail.com wrote: Hi, Huh. Can I ask where one would import * from sage.calculus.calculus? In my badly written code. I wanted to call symbolic_sum which is not reachable by default, rather than sum when doing some tests. I see. Why not just import that one function, in that case? That is a very natural thing to do. Only import a whole namespace if you really have to - it can really mess things up, as you have pointed out. What do you think about the other things - bugs, annoying, user error? - kcrisman -- 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: var() function behavior changes when calculus.py is imported
I see. Why not just import that one function, in that case? That is a very natural thing to do. Only import a whole namespace if you really have to - it can really mess things up, as you have pointed out. I'm aware of that, that piece of code was stupid because I was lazy when I wrote that. What do you think about the other things - bugs, annoying, user error? Do you mean about the different import of var() ? Both functions have in fact different uses and my problem arose because of my bad programming. I did not see it before, but it's stated in the note of calculus/ var.pyx var() function: The new variable is both returned and automatically injected into the global namespace. If you need symbolic variable in library code, it is better to use either SR.var() or SR.symbol(). So I guess there is no problem at all. I should have been more careful and less noisy. -- 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] solving equation question --- rounding error ?
Hi tvn, Am Montag, den 17.01.2011, 14:22 -0800 schrieb tvn: I try to solve for 3 variables x y z with 3 equations as below , I am expecting something like z = r1, x = -r1, y = -2*r1 but instead get x = y = z = 0 (which trivially valid though not expected). Is this because the numbers used too complex (equation 2) and have some rounding errors ? if not what's the cause and how to get around it ? Thanks sage version 4.6.1 solve([x + 0.106*y + 1.212*z == 0, 3.8759765625*x + 0.04801171875*y + 3.972*z == 0, 3.0625*x + 0.09325*y + 3.249*z == 0],[x,y,z]) [[x == 0, y == 0, z == 0]] #not expected sage: A = matrix([[1, 0.106, 1.212], [3.8759765625, 0.04801171875, 3.972], [3.0625, 0.09325, 3.249]]) sage: A.rank() 3 Thus (0,0,0) is the unique solution of your system. Cheers, Eckhard Is this due to rounding/precision error because if I replace the 2nd equation with another one then it works fine ? solve([x + 0.106*y + 1.212*z == 0, 2.25*x + 0.841*y + 3.932*z == 0, 3.0625*x + 0.09325*y + 3.249*z == 0],[x,y,z]) [[x == -r44, y == -2*r44, z == r44]]#expected -- 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 -- Service für Mathematik und Simulation Dr. Eckhard Kosin, selbständiger Diplom-Mathematiker Am Nymphenbad 14 D-81245 München, Germany Tel.: (+49)(+89) 88 88 479 Tel.,Fax: (+49)(+89) 835 844 mailto:e...@mathematik-service-kosin.de http://www.mathematik-service-kosin.de -- 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] plot problem
Hello everybody I am just looking at sketching graphs and I came across a problem that has me stumped. The graph I am trying to sketch is (x-3) / ( (x+1) * (x-2) ) now I have plotted the graph in sage on my TI-83 and at wolfram and they all different. Now I am thinking is sage right and the others wrong? or have I made an error inputting the equation? I would certainly welcome some help on the issue Thanks in advance Dan PS this is just for fun and not an exam piece or any test -- 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] plot problem
On Tue, Jan 18, 2011 at 2:35 PM, Daniel Harris mail.dhar...@googlemail.com wrote: Hello everybody I am just looking at sketching graphs and I came across a problem that has me stumped. The graph I am trying to sketch is (x-3) / ( (x+1) * (x-2) ) now I have plotted the graph in sage on my TI-83 and at wolfram and they all different. Now I am thinking is sage right and the others wrong? or have I made an error inputting the equation? I would certainly welcome some help on the issue What range are you plotting over? -1 x 1? -5 x 5? This could make a big difference on what the graph looks like. Likewise, what is the scale of the y-axis? I don't think Sage yet tries to remove the asymptotes at -1 and 2 from the plot. - 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
Re: [sage-support] solving equation question --- rounding error ?
On Tuesday, January 18, 2011 10:19:58 AM UTC-7, einek wrote: Hi tvn, Am Montag, den 17.01.2011, 14:22 -0800 schrieb tvn: I try to solve for 3 variables x y z with 3 equations as below , I am expecting something like z = r1, x = -r1, y = -2*r1 but instead get x = y = z = 0 (which trivially valid though not expected). Is this because the numbers used too complex (equation 2) and have some rounding errors ? if not what's the cause and how to get around it ? Thanks sage version 4.6.1 solve([x + 0.106*y + 1.212*z == 0, 3.8759765625*x + 0.04801171875*y + 3.972*z == 0, 3.0625*x + 0.09325*y + 3.249*z == 0],[x,y,z]) [[x == 0, y == 0, z == 0]] #not expected sage: A = matrix([[1, 0.106, 1.212], [3.8759765625, 0.04801171875, 3.972], [3.0625, 0.09325, 3.249]]) sage: A.rank() 3 Thus (0,0,0) is the unique solution of your system. x=1,y=2,z=-1 is another solution (in fact there are many solutions for this linear system of equations) . Cheers, Eckhard Is this due to rounding/precision error because if I replace the 2nd equation with another one then it works fine ? solve([x + 0.106*y + 1.212*z == 0, 2.25*x + 0.841*y + 3.932*z == 0, 3.0625*x + 0.09325*y + 3.249*z == 0],[x,y,z]) [[x == -r44, y == -2*r44, z == r44]]#expected -- To post to this group, send email to sage-s...@googlegroups.com To unsubscribe from this group, send email to sage-support +unsub...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org -- Service für Mathematik und Simulation Dr. Eckhard Kosin, selbständiger Diplom-Mathematiker Am Nymphenbad 14 D-81245 München, Germany Tel.: (+49)(+89) 88 88 479 Tel.,Fax: (+49)(+89) 835 844 mailto:e...@mathematik-service-kosin.de http://www.mathematik-service-kosin.de -- 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: solving equation question --- rounding error ?
Thus (0,0,0) is the unique solution of your system. Uh... not quite 'Thus'. The system in fact has an infinite number of unique solutions, as the original poster pointed out. Though I don't know why sage converges on [0,0,0]. Also just because a second sage method gives the same result as the first does not mean something isn't amiss. -- 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] plot problem
On Tue, Jan 18, 2011 at 10:51 PM, Robert Bradshaw rober...@math.washington.edu wrote: On Tue, Jan 18, 2011 at 2:35 PM, Daniel Harris mail.dhar...@googlemail.com wrote: Hello everybody I am just looking at sketching graphs and I came across a problem that has me stumped. The graph I am trying to sketch is (x-3) / ( (x+1) * (x-2) ) now I have plotted the graph in sage on my TI-83 and at wolfram and they all different. Now I am thinking is sage right and the others wrong? or have I made an error inputting the equation? I would certainly welcome some help on the issue What range are you plotting over? -1 x 1? -5 x 5? This could make a big difference on what the graph looks like. Likewise, what is the scale of the y-axis? I don't think Sage yet tries to remove the asymptotes at -1 and 2 from the plot. -1.5 x 3 the y peak at x=2 is the part that bothers me. It doesnt seem to show up on my calc or wolfram alpha? Dan - 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 -- 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: solving equation question --- rounding error ?
Hello, sage: A = matrix([[1, 0.106, 1.212], [3.8759765625, 0.04801171875, : 3.972], [3.0625, 0.09325, 3.249]]) sage: A.rank() 3 sage: A.det() 0.000 Though sage computes the rank to be 3, the determinant is negligible. Mathematica says the rank of this matrix is 2, and that its determinant is -4.02835*10^(-17) (and reduces the system to `z = -1.04202x + 0.0210102y`). Perhaps it's just an issue of the standard precision for floating point real numbers. The matrix in question is certainly very ill-conditioned. By the way, this system doesn't have an infinite number of unique solutions, though it does have an infinite number of distinct solutions (just a quibble...). -Keshav On Jan 19, 6:58 am, Ben Edwards bjedwa...@gmail.com wrote: Thus (0,0,0) is the unique solution of your system. Uh... not quite 'Thus'. The system in fact has an infinite number of unique solutions, as the original poster pointed out. Though I don't know why sage converges on [0,0,0]. Also just because a second sage method gives the same result as the first does not mean something isn't amiss. -- 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] Bug in implicit_plot?
In the following I expected the line $y=x$ in red for q; and the line
$y=-x$ in yellow for p. The plot for p is as desired, but the plot
for q contains also the line $y=-x$. This is using sage 4.6.1
#Is this a bug?
x,y=var('x y')
q=implicit_plot((x-y)/(x+y)==0,(x,-2,2),(y,-2,2),color='red')
p=implicit_plot((x+y)/(x-y)==0,(x,-2,2),(y,-2,2),color='yellow')
show(q)
show(p)
show(p+q)
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Re: [sage-support] solving equation question --- rounding error ?
On Tuesday, January 18, 2011 10:19:58 AM UTC-7, einek wrote: Hi tvn, Am Montag, den 17.01.2011, 14:22 -0800 schrieb tvn: I try to solve for 3 variables x y z with 3 equations as below , I am expecting something like z = r1, x = -r1, y = -2*r1 but instead get x = y = z = 0 (which trivially valid though not expected). Is this because the numbers used too complex (equation 2) and have some rounding errors ? if not what's the cause and how to get around it ? Thanks sage version 4.6.1 solve([x + 0.106*y + 1.212*z == 0, 3.8759765625*x + 0.04801171875*y + 3.972*z == 0, 3.0625*x + 0.09325*y + 3.249*z == 0],[x,y,z]) [[x == 0, y == 0, z == 0]] #not expected sage: A = matrix([[1, 0.106, 1.212], [3.8759765625, 0.04801171875, 3.972], [3.0625, 0.09325, 3.249]]) sage: A.rank() 3 Thus (0,0,0) is the unique solution of your system. The problem is rounding error. Over the rationals: sage: A = matrix(3, 3, [QQ(a) for a in [1, 0.106, 1.212, 3.8759765625, 0.04801171875, 3.972, 3.0625, 0.09325, 3.249]]) sage: A [ 1 53/500 303/250] [ 3969/1024 12291/256000 993/250] [ 49/16 373/40003249/1000] sage: A.rank() 2 - 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] Re: Errors When Starting Sage-4.6.1
Are you using the gentoo ebuild or are you installing just the Sage source tarball? The latter is designed to be installed in a users home directory. -- 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: plot problem
On Jan 18, 6:07 pm, Daniel Harris mail.dhar...@googlemail.com wrote: On Tue, Jan 18, 2011 at 10:51 PM, Robert Bradshaw rober...@math.washington.edu wrote: On Tue, Jan 18, 2011 at 2:35 PM, Daniel Harris mail.dhar...@googlemail.com wrote: Hello everybody I am just looking at sketching graphs and I came across a problem that has me stumped. The graph I am trying to sketch is (x-3) / ( (x+1) * (x-2) ) now I have plotted the graph in sage on my TI-83 and at wolfram and they all different. Now I am thinking is sage right and the others wrong? or have I made an error inputting the equation? I would certainly welcome some help on the issue What range are you plotting over? -1 x 1? -5 x 5? This could make a big difference on what the graph looks like. Likewise, what is the scale of the y-axis? I don't think Sage yet tries to remove the asymptotes at -1 and 2 from the plot. -1.5 x 3 the y peak at x=2 is the part that bothers me. It doesnt seem to show up on my calc or wolfram alpha? This is really showing the asymptote. If you do sage: plot((x-3) / ( (x+1) * (x-2) ) ,(x,-1.5,3)) sage: plot((x-3) / ( (x+1) * (x-2) ) ,(x,-1.5,3),ymin=-10,ymax=10) you'll see what I mean. Unfortunately we don't have any 'guessing' for the vertical range. That's a bug and a feature at the same time :) A graphing calculator likely just picks something arbitrary for that. - kcrisman -- 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 implicit_plot?
Here is a minimal example (implicit_plot does this, essentially):
sage: contour_plot(x/y==0,(x,-1,1),(y,-1,1), plot_points=150,
contours=(0,0), fill=False, cmap=[blue])
So the real question is why p *doesn't* have the 'wrong' line!
sage: C = contour_plot(x/y==0,(x,-1,1),(y,-1,1),plot_points=4,
contours=(0,0), fill=False, cmap=[blue])
sage: c = C[0]
sage: c.xy_data_array
[[1.0, 0.7, -0.33326, -1.0],
[2.9996, 1.0, -0.99967, -2.9996],
[-3.0009, -1.0004, 1.0, 3.0009],
[-1.0, -0.7, 0.33326, 1.0]]
And looking at the code for ContourPlot, this is somehow happening in
matplotlib.
else:
CS = subplot.contour(self.xy_data_array, contours,
cmap=cmap, extent=(x0,x1,y0,y1),
linewidths=linewidths,
linestyles=linestyles, label=options['legend_label'])
A mpl expert will have to take the story from here, but I suspect that
our use of subplot.contour is causing problems here - the
'contours=(0,0)' or something. Hope someone else chimes in!
- kcrisman
On Jan 18, 6:36 pm, adrian nihilalienumcr...@gmail.com wrote:
In the following I expected the line $y=x$ in red for q; and the line
$y=-x$ in yellow for p. The plot for p is as desired, but the plot
for q contains also the line $y=-x$. This is using sage 4.6.1
#Is this a bug?
x,y=var('x y')
q=implicit_plot((x-y)/(x+y)==0,(x,-2,2),(y,-2,2),color='red')
p=implicit_plot((x+y)/(x-y)==0,(x,-2,2),(y,-2,2),color='yellow')
show(q)
show(p)
show(p+q)
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Re: [sage-support] Re: Errors When Starting Sage-4.6.1
I am NOT using the ebuild. I just downloaded sage-4.6.1.tar, created a /usr/local/sage-4.6.1 directory, chowned that directory to my user, un-tared it, executed 'export MAKE=make -j12' then 'make make.out 21' and then a few hours later tried to run it with './sage'. I'll try compiling it in my home directory although I don't see how that would make a difference. Thanks for the reply. On 01/18/2011 04:32 PM, Volker Braun wrote: Are you using the gentoo ebuild or are you installing just the Sage source tarball? The latter is designed to be installed in a users home directory. -- 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 -- 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: Errors When Starting Sage-4.6.1
Thanks for the reply. I think I'll try to re-post on sage-devel.
(Although gcc-4.5.2 is in Gentoo's portage it is not in the 'stable'
branch yet. So I don't really know if I want to 'upgrade' gcc yet.)
On 01/18/2011 07:08 AM, Marshall Hampton wrote:
I have no real idea what is going wrong there - I've never used Gentoo
and I suspect it must be something to do with its infrastructure. But
one idea would be to retry with gcc 4.5.2; my impression is that there
are some significant improvements between the 4.4 and 4.5 series.
You might also want to repost this on sage-devel, since there might be
some Gentoo users who read that and not sage-support.
-M. Hampton
On Jan 17, 8:36 pm, Richard richj...@pacbell.net wrote:
After compiling sage-4.6.1 (again), without errors in install.log, I try
to start up sage and get the following:
/usr/local/sage-4.6.1]$ ./sage
--
| Sage Version 4.6.1, Release Date: 2011-01-11 |
| Type notebook() for the GUI, and license() for information.|
--
ERROR: An unexpected error occurred while tokenizing input
The following traceback may be corrupted or invalid
The error message is: ('EOF in multi-line statement', (1097, 0))
ERROR: An unexpected error occurred while tokenizing input
The following traceback may be corrupted or invalid
The error message is: ('EOF in multi-line statement', (1102, 0))
---
TypeError Traceback (most recent call last)
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/IPython/ipmaker.pyc
in force_import(modname)
64 reload(sys.modules[modname])
65 else:
--- 66 __import__(modname)
67
68
/usr/local/sage-4.6.1/local/bin/ipy_profile_sage.py in module()
5 preparser(True)
6
7 import sage.all_cmdline
8 sage.all_cmdline._init_cmdline(globals())
9
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/all_cmdline.py
in module()
12 try:
13
--- 14 from sage.all import *
15 from sage.calculus.predefined import x
16 preparser(on=True)
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/all.py in
module()
70 get_sigs()
71
--- 72 from sage.rings.all import *
73 from sage.matrix.all import *
74
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/rings/all.py in
module()
91
92 # Algebraic numbers
--- 93 from qqbar import (AlgebraicRealField, is_AlgebraicRealField, AA,
94AlgebraicReal, is_AlgebraicReal,
95AlgebraicField, is_AlgebraicField, QQbar,
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/rings/qqbar.py
in module()
4220 return isinstance(x, AlgebraicNumber)
4221
- 4222 QQbarPoly = PolynomialRing(QQbar, 'x')
4223 AAPoly = PolynomialRing(AA, 'x')
4224
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/rings/polynomial/polynomial_ring_constructor.pyc
in PolynomialRing(base_ring, arg1, arg2, sparse, order, names, name,
implementation)
341 raise TypeError, if second arguments is a
string with no commas, then there must be no other non-optional arguments
342 name = arg1
-- 343 R = _single_variate(base_ring, name, sparse,
implementation)
344 else:
345 # 2-4. PolynomialRing(base_ring, names,
order='degrevlex'):
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/rings/polynomial/polynomial_ring_constructor.pyc
in _single_variate(base_ring, name, sparse, implementation)
421
422 elif base_ring.is_field(proof = False):
-- 423 R = m.PolynomialRing_field(base_ring, name, sparse,
implementation=implementation)
424
425 elif base_ring.is_integral_domain(proof = False):
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/rings/polynomial/polynomial_ring.pyc
in __init__(self, base_ring, name, sparse, element_class, implementation)
1252 element_class =
polynomial_element_generic.Polynomial_generic_dense_field
1253
- 1254 PolynomialRing_integral_domain.__init__(self, base_ring,
name=name, sparse=sparse, element_class=element_class)
1255
1256 self._has_singular = can_convert_to_singular(self)
/usr/local/sage-4.6.1/local/lib/python2.6/site-packages/sage/rings/polynomial/polynomial_ring.pyc
in __init__(self, base_ring, name, sparse, implementation, element_class)
1187 raise ValueError, Unknown implementation %s
for ZZ[x]
1188 PolynomialRing_commutative.__init__(self, base_ring,
name=name,
- 1189 sparse=sparse,
Re: [sage-support] Re: Errors When Starting Sage-4.6.1
The error looks like it didn't build correctly. Is there anything suspicious in the install.log? Maybe rebuild the sage library (sage -ba). -- 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] Finite Group Homomorphism question
Hello all,
Running into an issue with something. I must be missing something. Say I
construct two groups that I know are isomorphic.
sage: G = SymmetricGroup(5)
sage: r = G('(1,2,5,4,3)')
sage: s = G('(1,5),(3,4)')
sage: H = G.subgroup([r,s])
sage: H
Subgroup of SymmetricGroup(5) generated by [(1,2,5,4,3), (1,5)(3,4)]
sage: D = DihedralGroup(5)
sage: D
Dihedral group of order 10 as a permutation group
I get an TypeError when I try and construct a homomorphism between these two
groups.
sage: phi = D.hom( ['(1,2,5,4,3)', '(1,5)(3,4)'] , H)
---
TypeError Traceback (most recent call last)
/Users/ayeq/Dropbox/src/sdsu-sage-tutorial/ipython console in module()
/Users/ayeq/sage/local/lib/python2.6/site-packages/sage/structure/parent_gens.so
in sage.structure.parent_gens.ParentWithGens.hom
(sage/structure/parent_gens.c:3858)()
/Users/ayeq/sage/local/lib/python2.6/site-packages/sage/categories/homset.pyc
in __call__(self, x, y, check, on_basis)
432 return self.element_class_set_morphism(self, x)
433
-- 434 raise TypeError, Unable to coerce x (=%s) to a morphism in
%s%(x,self)
435
436 @lazy_attribute
TypeError: Unable to coerce x (=['(1,2,5,4,3)', '(1,5)(3,4)']) to a morphism
in Set of Morphisms from Dihedral group of order 10 as a permutation group
to Subgroup of SymmetricGroup(5) generated by [(1,2,5,4,3), (1,5)(3,4)] in
Category of finite permutation groups
I have tried to do this in a few different ways. (by coercing the elements
first, etc...) Can somebody see what I am missing? Thank you in advance.
--
D. M. Monarres
dmmonar...@gmail.com
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[sage-support] Re: Finite Group Homomorphism question
Ignore. I was stupid. Sorry for wasting bits.
--
D. M. Monarres
dmmonar...@gmail.com
On Tue, Jan 18, 2011 at 7:30 PM, D. M. Monarres dmmonar...@gmail.comwrote:
Hello all,
Running into an issue with something. I must be missing something. Say I
construct two groups that I know are isomorphic.
sage: G = SymmetricGroup(5)
sage: r = G('(1,2,5,4,3)')
sage: s = G('(1,5),(3,4)')
sage: H = G.subgroup([r,s])
sage: H
Subgroup of SymmetricGroup(5) generated by [(1,2,5,4,3), (1,5)(3,4)]
sage: D = DihedralGroup(5)
sage: D
Dihedral group of order 10 as a permutation group
I get an TypeError when I try and construct a homomorphism between these
two groups.
sage: phi = D.hom( ['(1,2,5,4,3)', '(1,5)(3,4)'] , H)
---
TypeError Traceback (most recent call last)
/Users/ayeq/Dropbox/src/sdsu-sage-tutorial/ipython console in module()
/Users/ayeq/sage/local/lib/python2.6/site-packages/sage/structure/parent_gens.so
in sage.structure.parent_gens.ParentWithGens.hom
(sage/structure/parent_gens.c:3858)()
/Users/ayeq/sage/local/lib/python2.6/site-packages/sage/categories/homset.pyc
in __call__(self, x, y, check, on_basis)
432 return self.element_class_set_morphism(self, x)
433
-- 434 raise TypeError, Unable to coerce x (=%s) to a morphism in
%s%(x,self)
435
436 @lazy_attribute
TypeError: Unable to coerce x (=['(1,2,5,4,3)', '(1,5)(3,4)']) to a
morphism in Set of Morphisms from Dihedral group of order 10 as a
permutation group to Subgroup of SymmetricGroup(5) generated by
[(1,2,5,4,3), (1,5)(3,4)] in Category of finite permutation groups
I have tried to do this in a few different ways. (by coercing the elements
first, etc...) Can somebody see what I am missing? Thank you in advance.
--
D. M. Monarres
dmmonar...@gmail.com
--
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[sage-support] Re: Finite Group Homomorphism question
On Jan 18, 7:30 pm, D. M. Monarres dmmonar...@gmail.com wrote:
Hello all,
Running into an issue with something. I must be missing something. Say I
construct two groups that I know are isomorphic.
sage: G = SymmetricGroup(5)
sage: r = G('(1,2,5,4,3)')
sage: s = G('(1,5),(3,4)')
sage: H = G.subgroup([r,s])
sage: H
Subgroup of SymmetricGroup(5) generated by [(1,2,5,4,3), (1,5)(3,4)]
sage: D = DihedralGroup(5)
sage: D
Dihedral group of order 10 as a permutation group
I get an TypeError when I try and construct a homomorphism between these two
groups.
sage: phi = D.hom( ['(1,2,5,4,3)', '(1,5)(3,4)'] , H)
---
TypeError Traceback (most recent call last)
/Users/ayeq/Dropbox/src/sdsu-sage-tutorial/ipython console in module()
/Users/ayeq/sage/local/lib/python2.6/site-packages/sage/structure/parent_ge
ns.so
in sage.structure.parent_gens.ParentWithGens.hom
(sage/structure/parent_gens.c:3858)()
/Users/ayeq/sage/local/lib/python2.6/site-packages/sage/categories/homset.p yc
in __call__(self, x, y, check, on_basis)
432 return self.element_class_set_morphism(self, x)
433
-- 434 raise TypeError, Unable to coerce x (=%s) to a morphism in
%s%(x,self)
435
436 @lazy_attribute
TypeError: Unable to coerce x (=['(1,2,5,4,3)', '(1,5)(3,4)']) to a morphism
in Set of Morphisms from Dihedral group of order 10 as a permutation group
to Subgroup of SymmetricGroup(5) generated by [(1,2,5,4,3), (1,5)(3,4)] in
Category of finite permutation groups
I have tried to do this in a few different ways. (by coercing the elements
first, etc...) Can somebody see what I am missing? Thank you in advance.
This looks like a bug to me, but I'm not sure. Anyway, you can do
this:
sage: PermutationGroupMorphism(D, H, D.gens(), H.gens())
Homomorphism : Dihedral group of order 10 as a permutation group --
Subgroup of SymmetricGroup(5) generated by [(1,2,5,4,3), (1,5)(3,4)]
(I don't know why D.hom(H.gens(), H) doesn't do the same thing...)
--
John
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Re: [sage-support] Re: Finite Group Homomorphism question
Thanks for the other command. I am writing a tutorial for my university and
am running into quite a few of these little gotcha's with these sort of
things.
--
D. M. Monarres
dmmonar...@gmail.com
On Tue, Jan 18, 2011 at 8:28 PM, John H Palmieri jhpalmier...@gmail.comwrote:
On Jan 18, 7:30 pm, D. M. Monarres dmmonar...@gmail.com wrote:
Hello all,
Running into an issue with something. I must be missing something. Say I
construct two groups that I know are isomorphic.
sage: G = SymmetricGroup(5)
sage: r = G('(1,2,5,4,3)')
sage: s = G('(1,5),(3,4)')
sage: H = G.subgroup([r,s])
sage: H
Subgroup of SymmetricGroup(5) generated by [(1,2,5,4,3), (1,5)(3,4)]
sage: D = DihedralGroup(5)
sage: D
Dihedral group of order 10 as a permutation group
I get an TypeError when I try and construct a homomorphism between these
two
groups.
sage: phi = D.hom( ['(1,2,5,4,3)', '(1,5)(3,4)'] , H)
---
TypeError Traceback (most recent call
last)
/Users/ayeq/Dropbox/src/sdsu-sage-tutorial/ipython console in
module()
/Users/ayeq/sage/local/lib/python2.6/site-packages/sage/structure/parent_ge
ns.so
in sage.structure.parent_gens.ParentWithGens.hom
(sage/structure/parent_gens.c:3858)()
/Users/ayeq/sage/local/lib/python2.6/site-packages/sage/categories/homset.p
yc
in __call__(self, x, y, check, on_basis)
432 return self.element_class_set_morphism(self, x)
433
-- 434 raise TypeError, Unable to coerce x (=%s) to a morphism
in
%s%(x,self)
435
436 @lazy_attribute
TypeError: Unable to coerce x (=['(1,2,5,4,3)', '(1,5)(3,4)']) to a
morphism
in Set of Morphisms from Dihedral group of order 10 as a permutation
group
to Subgroup of SymmetricGroup(5) generated by [(1,2,5,4,3), (1,5)(3,4)]
in
Category of finite permutation groups
I have tried to do this in a few different ways. (by coercing the
elements
first, etc...) Can somebody see what I am missing? Thank you in advance.
This looks like a bug to me, but I'm not sure. Anyway, you can do
this:
sage: PermutationGroupMorphism(D, H, D.gens(), H.gens())
Homomorphism : Dihedral group of order 10 as a permutation group --
Subgroup of SymmetricGroup(5) generated by [(1,2,5,4,3), (1,5)(3,4)]
(I don't know why D.hom(H.gens(), H) doesn't do the same thing...)
--
John
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