[sage-support] Re: why is this contour integral wrong?
On Dec 5, 5:31 am, Dan Drake dr...@kaist.edu wrote:
I keep wondering whether Sage is making a mistake, or I'm not
understanding complex analysis. I'm a little afraid to learn the answer.
:)
Take f(z) = (z-I)*(z-1)^2/(z-(-1/2-I/3)). It's analytic everywhere
except at -1/2-I/3, where it has a simple pole. So, if I integrate over
a circle centered at 0 of radius, say, 2, the answer should be
2*pi*I*(residue of f at -1/2 - I/3),
which is pi*(181/27 + 19*I/36). However, when I try to do the contour
integral, I get:
sage: integrate(f(2*exp(I*t)) * 2*I*exp(I*t), (t, 0, 2*pi))
0
even though the contour encloses the pole. It works if I center the
circle around the pole:
sage: integrate(f(-1/2-I/3 + exp(I*t)) * I*exp(I*t), (t, 0, 2*pi))
(19/36*I + 181/27)*pi
and also if I integrate over the square with vertices 1+i, 1-i, -1-i,
-1+i. What's wrong with the circle at the origin?
Note that Mathematica gets this right, although you need to ask for full
simplification: with f[z_] = (z-I)*(z-1)^2/(z-(-1/2-I/3)), you get
In[5]:= Integrate[f[2*Exp[I*t]] * 2*I*Exp[I*t], {t, 0, 2*Pi}]//FullSimplify
181 19 I
Out[5]= (--- + ) Pi
27 36
Any ideas?
Dan
--
--- Dan Drake
- http://mathsci.kaist.ac.kr/~drake
---
signature.asc
1KViewDownload
sage: maxima('rectform(2*%pi*%i*residue((z-%i)*(z-1)^2/(z-(-1/2-%i/
3)),z,-1/2-%i/3))').sage()
(19/36*I + 181/27)*pi
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Re: [sage-support] Re: Win 7 64 Host and SAGE/Fedora guest on VMware or Virtualbox
I'm doing my masters at the moment and I plan on running sage quite a bit for now, both via the VM and a local linux install. I can try one image a month for you guys (The cap is a bit of an issue), and I'll try break each distro during my coffee breaks :P May be it'd help to setup a page on what to do when X happens :) I'll read through the links you've sent a little later. Thanks for the assistance once again. On Fri, Dec 2, 2011 at 10:28 AM, emil emil.widm...@gmail.com wrote: On Dec 1, 11:42 pm, Carel van Dam carelv...@gmail.com wrote: Hi Mr. Widmann and Mr Braun, Thanks for your responses, sorry my reply has been slow. I'll try out your distro during the week Mr. Widmann, I ran out of cap last month :S. The Read Me I was referring to was both of the Read Me's on the Sage download site. I can't remember which one I'm afraid. As to the *.ovf, I got that by extracting the *.ova file, some old instructions I found on google told me to do that :S I'm now using the OVA's as supplied. In the *.ova, I had er... Sage 4.7.1, the problem still persists, some how the network settings were broken when I played around with the VM router File Preferrences (Ctrl+G) Network Virtual Box Adapter (Select) Edit (Space) make changes applicable to your system. The network settings for the VM as per Mr. Braun's instructions are also to do with it. Since My last e-mail and your replies I got the 4.7.2 ova and the problem seems to have fixed itself I also installed an Open SUSE VM to check I could get the network working with the VM and this seemed to work fine, both using NAT and the Bridged adaptor. Yesterday when I took the PC to another network, that broke the sage VM again. I fixed it this time by deleting the VM and re-importing, you loose your files that way but it atleast gets you running again. I believe the problem is with virtualbox and not the distribution, so thank you for your time spent helping me. I'll keep pocking around a bit, If I find anything that may be of use to some one who reads this mailing list then I'll reply here again, mostly because I've seen this question asked a few times on the web but it's seldomly replied to/solved. regards, Carel Hello Mr. van Dam, thank you for your detailed response. It is very helpful. The developement of the virtual machine image - although the most popular distribution of sage - is still kind of a fringe topic in sage developement. To have more people contributing, even if it is just short feedback about arising problems, could make an considerable impact about the quality of this product (and I explicitly include documentation/troubleshooting as one of the most important things). You are right that using virtualisation has its own tricks and pitfalls. About your problem with the lost net connection: I am shooting in the blue here, but it could be related to an existing MAC adress of the VM and some settings in the /etc/udev folder. Please read here: http://www.linuxquestions.org/questions/debian-26/no-network-on-virtualbox-udev-problem-822023/ https://www.virtualbox.org/ticket/2286 https://forums.virtualbox.org/viewtopic.php?t=7749highlight=udev If the network connectivity is lost I sometimes had success by just going to the network section of the Virtual Box GUI and unselect and reselect the adapter. Sometimes there are other issues - the last days and I installed and uninstalled VMs repeadetly. At one point - network was not working and I had absolutely no clue why - I had to log into my router because the dhcpd server had run out of possible new adresses and I had to increase the available pool - I don't think this was the problem in your case, just to show that there are some hard to find pitfalls. To improve and ease the distribution of the sage VM I built an integrated VirtualBox Sage VM installer the last days. To develope this further I need some feedback and testers. I know this needs some commitment of time and Bandwith but it is just a humble invitation to help to make sage an easier experience for a lot of users. I have announced this installer and the download link (650 MB) here: http://groups.google.com/group/sage-windows/browse_thread/thread/ca801cbfc5b9170d kind regards emil -- 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: Win 7 64 Host and SAGE/Fedora guest on VMware or Virtualbox
On Dec 5, 9:14 am, Carel van Dam carelv...@gmail.com wrote: I'm doing my masters at the moment and I plan on running sage quite a bit for now, both via the VM and a local linux install. I can try one image a month for you guys (The cap is a bit of an issue), and I'll try break each distro during my coffee breaks :P May be it'd help to setup a page on what to do when X happens :) That sounds great! about the site - it would be an idea to expand http://wiki.sagemath.org/faq#How_do_I_run_Sage_with_VirtualBox.3F there is already a small pool of questions here and also on ask.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] Unicode characters in axes labels?
Hello!
I am trying to use unicode characters in axes labels and it fails with
exception:
P = plot_step_function([(i,prime_pi(i)) for i in
range(20)],thickness=2,color='black')
P.show(axes=False,frame=True,axes_labels=('текс','x'))
Traceback (most recent call last):
File stdin, line 1, in module
File _sage_input_28.py, line 10, in module
exec compile(u'open(___code___.py,w).write(# -*- coding:
utf-8 -*-\\n +
_support_.preparse_worksheet_cell(base64.b64decode(UC5zaG93KGF4ZXM9RmFsc2UsZnJhbWU9VHJ1ZSxheGVzX2xhYmVscz0oJ9GC0LXQutGBJywneCcpKQ==),globals())
+\\n); execfile(os.path.abspath(___code___.py))
File , line 1, in module
File /tmp/tmpzOkGkv/___code___.py, line 2, in module
exec
compile(uP.show(axes=False,frame=True,axes_labels=('\u0442\u0435\u043a
\u0441','x')) + '\n', '', 'single')
File , line 1, in module
File /home/sage/sage/local/lib/python2.6/site-packages/sage/misc/
decorators.py, line 456, in wrapper
return func(*args, **kwds)
File /home/sage/sage/local/lib/python2.6/site-packages/sage/plot/
plot.py, line 1750, in show
self.save(**kwds)
File /home/sage/sage/local/lib/python2.6/site-packages/sage/misc/
decorators.py, line 456, in wrapper
return func(*args, **kwds)
File /home/sage/sage/local/lib/python2.6/site-packages/sage/plot/
plot.py, line 2484, in save
transparent=transparent)
File /home/sage/sage/local/lib/python2.6/site-packages/matplotlib/
figure.py, line 1084, in savefig
self.canvas.print_figure(*args, **kwargs)
File /home/sage/sage/local/lib/python2.6/site-packages/matplotlib/
backend_bases.py, line 1889, in print_figure
**kwargs)
File /home/sage/sage/local/lib/python2.6/site-packages/matplotlib/
backends/backend_agg.py, line 438, in print_png
FigureCanvasAgg.draw(self)
File /home/sage/sage/local/lib/python2.6/site-packages/matplotlib/
backends/backend_agg.py, line 394, in draw
self.figure.draw(self.renderer)
File /home/sage/sage/local/lib/python2.6/site-packages/matplotlib/
artist.py, line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File /home/sage/sage/local/lib/python2.6/site-packages/matplotlib/
figure.py, line 798, in draw
func(*args)
File /home/sage/sage/local/lib/python2.6/site-packages/matplotlib/
artist.py, line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File /home/sage/sage/local/lib/python2.6/site-packages/matplotlib/
axes.py, line 1946, in draw
a.draw(renderer)
File /home/sage/sage/local/lib/python2.6/site-packages/matplotlib/
artist.py, line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File /home/sage/sage/local/lib/python2.6/site-packages/matplotlib/
axis.py, line 1032, in draw
self.label.draw(renderer)
File /home/sage/sage/local/lib/python2.6/site-packages/matplotlib/
artist.py, line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File /home/sage/sage/local/lib/python2.6/site-packages/matplotlib/
text.py, line 526, in draw
bbox, info = self._get_layout(renderer)
File /home/sage/sage/local/lib/python2.6/site-packages/matplotlib/
text.py, line 305, in _get_layout
clean_line, ismath = self.is_math_text(line)
File /home/sage/sage/local/lib/python2.6/site-packages/matplotlib/
text.py, line 989, in is_math_text
if cbook.is_math_text(s):
File /home/sage/sage/local/lib/python2.6/site-packages/matplotlib/
cbook.py, line 1793, in is_math_text
s = unicode(s)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xd1 in position
0: ordinal not in range(128)
I found this topic:
https://groups.google.com/group/sage-support/browse_thread/thread/9908f1869c7d7f45/1cc9473c667c162c?hl=enlnk=gstq=unicode+axes+labels#1cc9473c667c162c
No responses :(
Could anyone please suggest me something to workaround this problem?
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[sage-support] Re: why is this contour integral wrong?
On Dec 5, 10:04 am, achrzesz achrz...@wp.pl wrote:
On Dec 5, 5:31 am, Dan Drake dr...@kaist.edu wrote:
I keep wondering whether Sage is making a mistake, or I'm not
understanding complex analysis. I'm a little afraid to learn the answer.
:)
Take f(z) = (z-I)*(z-1)^2/(z-(-1/2-I/3)). It's analytic everywhere
except at -1/2-I/3, where it has a simple pole. So, if I integrate over
a circle centered at 0 of radius, say, 2, the answer should be
2*pi*I*(residue of f at -1/2 - I/3),
which is pi*(181/27 + 19*I/36). However, when I try to do the contour
integral, I get:
sage: integrate(f(2*exp(I*t)) * 2*I*exp(I*t), (t, 0, 2*pi))
0
even though the contour encloses the pole. It works if I center the
circle around the pole:
sage: integrate(f(-1/2-I/3 + exp(I*t)) * I*exp(I*t), (t, 0, 2*pi))
(19/36*I + 181/27)*pi
and also if I integrate over the square with vertices 1+i, 1-i, -1-i,
-1+i. What's wrong with the circle at the origin?
Note that Mathematica gets this right, although you need to ask for full
simplification: with f[z_] = (z-I)*(z-1)^2/(z-(-1/2-I/3)), you get
In[5]:= Integrate[f[2*Exp[I*t]] * 2*I*Exp[I*t], {t, 0, 2*Pi}]//FullSimplify
181 19 I
Out[5]= (--- + ) Pi
27 36
Any ideas?
Dan
--
--- Dan Drake
- http://mathsci.kaist.ac.kr/~drake
---
signature.asc
1KViewDownload
sage: maxima('rectform(2*%pi*%i*residue((z-%i)*(z-1)^2/(z-(-1/2-%i/
3)),z,-1/2-%i/3))').sage()
(19/36*I + 181/27)*pi
sage: f(z) = (z-I)*(z-1)^2/(z-(-1/2-I/3))
sage: 2*pi*I*f(z).maxima_methods().residue(z,-1/2 - I/3)
(19/36*I + 181/27)*pi
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[sage-support] Define polynomial rings of given variables
If I have a boolean expression of a certain number of variables, how do I define a polynomial ring with them.. For example, let (x0,x1,x2,x3,x4,x5,x6,x7) be a set of variables, and I have an expression S = x0 + x1*x3 + x7 I need to define the polynomial ring R.x0,x1,x3,x7=BooleanPolynomialRing(4) This exercise is fine, if the number of variables is small , but what is the solution if the number of variables is large. Thank You Subhadeep Banik Senior Research Fellow Applied Statistics Unit Indian Statistical Institute Kolkata Phone : 91 9433037829 (M) 91 33 - 25741829 (H) -- 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: Define polynomial rings of given variables
R=BooleanPolynomialRing(100,['x'+str(i) for i in [1..100]]) R.inject_variables()# if you don't really need the identifiers in Python's namespace, better skip this On Dec 5, 6:18 am, Subhadeep Banik monsieurlel...@gmail.com wrote: If I have a boolean expression of a certain number of variables, how do I define a polynomial ring with them.. For example, let (x0,x1,x2,x3,x4,x5,x6,x7) be a set of variables, and I have an expression S = x0 + x1*x3 + x7 I need to define the polynomial ring R.x0,x1,x3,x7=BooleanPolynomialRing(4) This exercise is fine, if the number of variables is small , but what is the solution if the number of variables is large. Thank You Subhadeep Banik Senior Research Fellow Applied Statistics Unit Indian Statistical Institute Kolkata Phone : 91 9433037829 (M) 91 33 - 25741829 (H) -- 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: why is this contour integral wrong?
So it sounds like you should file a ticket, Dan. Maybe we're just sending it to Maxima wrong. (%i9) f(z):=(z-%i)*(z-1)^2/(z-(-1/2-%i/3)); 2 (z - %i) (z - 1) (%o9) f(z) := - - 1 %i z - (--- - --) 23 (%i14) display2d:false; (%o14) false (%i15) integrate(f(-1/2-%i/3+exp(%i*t))*%i*exp(%i*t),t,0,2*%pi); (%o15) %i*((4*%i-13)/3-((724*%i-57)*%pi+144*%i-468)/108) (%i17) rectform(%i*((4*%i-13)/3-((724*%i-57)*%pi+144*%i-468)/108)); (%o17) (724*%pi+144)/108+%i*(-(-57*%pi-468)/108-13/3)-4/3 Is this right? -- 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: Define polynomial rings of given variables
On Dec 5, 3:18 pm, Subhadeep Banik monsieurlel...@gmail.com wrote: If I have a boolean expression of a certain number of variables, how do I define a polynomial ring with them.. For example, let (x0,x1,x2,x3,x4,x5,x6,x7) be a set of variables, and I have an expression S = x0 + x1*x3 + x7 I need to define the polynomial ring R.x0,x1,x3,x7=BooleanPolynomialRing(4) This exercise is fine, if the number of variables is small , but what is the solution if the number of variables is large. Thank You Subhadeep Banik If you need a polynomial ring with selected variables then you can try for example R=PolynomialRing(GF(2),'x',2^8) x=R.gens() S=x[253]+x[254]*x[255] xx=S.variables() l=len(xx) P=BooleanPolynomialRing(l,map(str,xx)) Andrzej Chrzeszczyk Senior Research Fellow Applied Statistics Unit Indian Statistical Institute Kolkata Phone : 91 9433037829 (M) 91 33 - 25741829 (H) -- 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] sagenb down
Hi sagenb doesn't seem to be working. A student of mine is about to defenestrate herself (her words) because it's not working. If this is expected downtime; my apologies -- she wasn't supposed to be using sagenb in the first place, but that's life. :-) regards john perry -- 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] sagenb down
test.sagenb.org seems to be up, so if she has a saved local copy of a worksheet, she could use that.. Doug -- 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] sagenb down
On Dec 5, 2011 9:47 AM, john_perry_usm john.pe...@usm.edu wrote: Hi sagenb doesn't seem to be working. A student of mine is about to defenestrate herself (her words) because it's not working. If this is expected downtime; my apologies -- she wasn't supposed to be using sagenb in the first place, but that's life. :-) I have just initiated restarting the server. regards john perry -- 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] Finding numerical solutions to an inequality in multiple variables
Hi, all,
I'm new here and new-ish to sage and I was hoping you could help me
with a rather complicated problem. My professor gave me this
inequality:
0 (2*n*(i+j+k))/(-k*n+j*(n-s)+i*s) 1
and he wants me to see if I can find solutions within the following
constraints: 0 s n, i,j,k integers, and i = j+k, j = i+k, k=i
+j.
It seemed like it would be possible to get Sage to do this for me, and
sure enough, when i input:
sage: n = var('n')
sage: sage: s = var('s')
sage: sage: assume(s0)
sage: sage: assume(ns)
sage: sage: i = var('i')
sage: sage: j = var('j')
sage: sage: k = var('k')
sage: sage: assume(i,'integer')
sage: sage: assume(j,'integer')
sage: sage: assume(k,'integer')
sage: assume(i=j+k)
sage: assume(j=i+k)
sage: assume(k=i+j)
sage: solve((0 (2*n*(i+j+k))/(-k*n+j*(n-s)+i*s) 1),n)
I got a result, namely:
[[k -i - j, 0 n, -i*s - j*n + j*s + k*n 0], [-i - j k, n 0, -
i*s - j*n + j*s + k*n 0], [-i - j k, 0 n, i*s + j*n - j*s - k*n
0], [k -i - j, n 0, i*s + j*n - j*s - k*n 0]]
My problem is, first, that I'm not sure the solutions are correct--
note that some of them have n 0, when I'm assuming the contrary (and
when I try to have it assume explicitly that n 0, Sage will tell me
that my assumption is redundant); and second, that I'm not sure how to
get specific numbers out of this. I've tried assigning specific values
to the variables, one by one, but I keep getting equations that don't
work, or simply []
Does anyone know what's going on, and if this problem is solvable in
sage?
Thank you!
Cal
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[sage-support] Re: sagenb down
On 12/5/11 11:54 AM, William Stein wrote: On Dec 5, 2011 9:47 AM, john_perry_usm john.pe...@usm.edu mailto:john.pe...@usm.edu wrote: Hi sagenb doesn't seem to be working. A student of mine is about to defenestrate herself (her words) because it's not working. If this is expected downtime; my apologies -- she wasn't supposed to be using sagenb in the first place, but that's life. :-) I have just initiated restarting the server. It looks like it's another mess of filedescriptor errors: 2011-12-05 09:54:07-0800 [-] Unhandled Error Traceback (most recent call last): File /sagenb/sage_install/sage-4.7.2/local/lib/python2.6/site-packages/Twisted-11.0.0-py2.6-linux-x86_64.egg/twisted/application/app.py, line 392, in startReactor self.config, oldstdout, oldstderr, self.profiler, reactor) File /sagenb/sage_install/sage-4.7.2/local/lib/python2.6/site-packages/Twisted-11.0.0-py2.6-linux-x86_64.egg/twisted/application/app.py, line 313, in runReactorWithLogging reactor.run() File /sagenb/sage_install/sage-4.7.2/local/lib/python2.6/site-packages/Twisted-11.0.0-py2.6-linux-x86_64.egg/twisted/internet/base.py, line 1162, in run self.mainLoop() File /sagenb/sage_install/sage-4.7.2/local/lib/python2.6/site-packages/Twisted-11.0.0-py2.6-linux-x86_64.egg/twisted/internet/base.py, line 1174, in mainLoop self.doIteration(t) --- exception caught here --- File /sagenb/sage_install/sage-4.7.2/local/lib/python2.6/site-packages/Twisted-11.0.0-py2.6-linux-x86_64.egg/twisted/internet/selectreactor.py, line 104, in doSelect [], timeout) exceptions.ValueError: filedescriptor out of range in select() 2011-12-05 09:54:07-0800 [-] Malformed file descriptor found. Preening lists. 2011-12-05 09:54:07-0800 [-] bad descriptor HTTPChannel #190108 on Thanks, Jason -- 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: Finding numerical solutions to an inequality in multiple variables
I don't think maxima does polyhedral computations in its assume facility, so you probably get the wrong answer. We do, however, have quite a lot of tools for polyhedral computations: sage: P = Polyhedron(ieqs=[(1,2), (10,-7)]) sage: P A 1-dimensional polyhedron in QQ^1 defined as the convex hull of 2 vertices sage: P.Hrepresentation() (An inequality (-7) x + 10 = 0, An inequality (2) x + 1 = 0) sage: P.Vrepresentation() (A vertex at (10/7), A vertex at (-1/2)) sage: P.integral_points() ((0), (1)) -- 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: sagenb down
On Dec 5, 11:54 am, William Stein wst...@gmail.com wrote: On Dec 5, 2011 9:47 AM, john_perry_usm john.pe...@usm.edu wrote: sagenb doesn't seem to be working. A student of mine is about to defenestrate herself (her words) because it's not working. ... I have just initiated restarting the server. Our windows thank you. 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
[sage-support] Re: sagenb down
On 12/5/11 11:47 AM, john_perry_usm wrote: defenestrate herself (her words) For the curious: http://en.wikipedia.org/wiki/Defenestration Defenestration is the act of throwing someone or something out of a window.[1] The term defenestration was coined around the time of an incident in Prague Castle in the year 1618. The word comes from the Latin de- (down or away from) and fenestra (window or opening).[2] Likewise, it can also refer to the condition of being thrown out of a window, as in The Defenestration of Ermintrude Inch.[3] (also http://www.merriam-webster.com/dictionary/defenestrate for those that don't trust wikipedia) Wow. What a great word. I hope she doesn't defenestrate herself! Thanks, Jason -- 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: Jmol on Android tablet
On Sat, Nov 26, 2011 at 10:12 PM, pong wypon...@gmail.com wrote: Thanks for the tips, but I would like to have live 3D-plots (ones that one can spin and drag around). In theory, doing this (written by Bill Cauchois) should work, but it doesn't work on Android: I = icosahedron() I.show(viewer='canvas3d') The plot appears, but there is no way to rotate it around with your finger. You can on a normal computer with a mouse, but unfortunately this doesn't currently translate into touch (yet). William On Nov 26, 6:56 pm, A. Jorge Garcia calcp...@aol.com wrote: pong wypon...@gmail.com wrote: Two days ago during Thanksgiving dinner, I tried showing SAGE notebook to my cousin who has an Android tablet. Well... I then realized that Jmol (or rather Java runtime environment) is not supported on android (at least not out of the box) My questions are: 1) Has someone successfully run Jmol on an Android browser? There is a youtube clip showing Jmol 12.3 is working on Android:http://www.youtube.com/watch?v=og-lXFnDU-w 2) If so, what's the best way to make that happen? Thanks in advance -- 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 On my android phone, I use show(viewer=tachyon) instead of jmol. HTH, A. Jorge Garcia Applied Math and CompScihttp://shadowfaxrant.blogspot.comhttp://www.youtube.com/calcpage2009 Sent via DROID on Verizon Wireless -- 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 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] Re: why is this contour integral wrong?
On Dec 5, 4:56 pm, kcrisman kcris...@gmail.com wrote: So it sounds like you should file a ticket, Dan. Maybe we're just sending it to Maxima wrong. (%i9) f(z):=(z-%i)*(z-1)^2/(z-(-1/2-%i/3)); 2 (z - %i) (z - 1) (%o9) f(z) := - - 1 %i z - (--- - --) 2 3 (%i14) display2d:false; (%o14) false (%i15) integrate(f(-1/2-%i/3+exp(%i*t))*%i*exp(%i*t),t,0,2*%pi); (%o15) %i*((4*%i-13)/3-((724*%i-57)*%pi+144*%i-468)/108) (%i17) rectform(%i*((4*%i-13)/3-((724*%i-57)*%pi+144*%i-468)/108)); (%o17) (724*%pi+144)/108+%i*(-(-57*%pi-468)/108-13/3)-4/3 Is this right? Applying expand(ratsimp( )); to your %o15 one can obtain Dan's result. The problem is that the integral should not depend on the center of the circle containing the pole. It looks like maxima bug (?) -- 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: Finding numerical solutions to an inequality in multiple variables
That would explain why it wasn't working. I've never done polyhedral computations before, but I will look at your example and the reference manual and see what I can do! Thank you! On Dec 5, 1:45 pm, Volker Braun vbraun.n...@gmail.com wrote: I don't think maxima does polyhedral computations in its assume facility, so you probably get the wrong answer. We do, however, have quite a lot of tools for polyhedral computations: sage: P = Polyhedron(ieqs=[(1,2), (10,-7)]) sage: P A 1-dimensional polyhedron in QQ^1 defined as the convex hull of 2 vertices sage: P.Hrepresentation() (An inequality (-7) x + 10 = 0, An inequality (2) x + 1 = 0) sage: P.Vrepresentation() (A vertex at (10/7), A vertex at (-1/2)) sage: P.integral_points() ((0), (1)) -- 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: computing the cup-product in the cohomology of a simplicial complex
Here is a first implementation of the cup product. I hope (of course) that the code is correct, but it is certainly not very idomatic. Any suggestions for improvement are welcome! def cup_product(X,c1,dim1,c2,dim2): d = dim1 + dim2 faces1 = list(X.n_faces(dim1)) faces2 = list(X.n_faces(dim2)) faces = list(X.n_faces(d)) res = [] for sigma in faces: sigma1 = Simplex(sigma[0:dim1+1]) sigma2 = Simplex(sigma[dim1:d+1]) index1 = faces1.index(sigma1) index2 = faces2.index(sigma2) coeff1 = c1[index1] coeff2 = c2[index2] coeff = coeff1 * coeff2 res.append(coeff) return vector(tuple(res)) To use it on the Torus, for example, you can do this: X = simplicial_complexes.Torus() C = X.chain_complex(cochain=True) H = C.homology(generators=True) gen1 = H[1][1][0] gen2 = H[1][1][1] d1 = C.differential()[1] q = cup_product(X,gen1,1,gen1,1) print q print d1.solve_right(q) p = cup_product(X,gen1,1,gen2,1) print p print d1.solve_right(p) #error The last line throws an error, because p is not in the image of d1. This shows that p, the cup product of the two generator of the cohomology group in degree 1, is a non-trivial element of the cohomology group in degree 2. If there is interest, I would be willing to put in the additional work to add this function to Sage. But for that I would need to learn about the all the other issues that I don't know anything about but that I should take care of first :) Cheers, Felix -- 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] some problem with installation on winxp
Hi I am trying to set up sage using vitualbox. What base memory should I set in virtualbox for the sage ? While setting up, I assigned 1024 MB base memory. Later the Virtualbox keeps reminding me that base memory is more than 50 % of total memory (1.74 GB) and there might be problems. I also don't know how to change the base memory in Virtualbox ? So please let me know what base memory should be set and how to change the already given amount in Virtualbox Thanks -- 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
