[sage-support] Korean characters in TinyMCE
Hi, If I write in Korean and save in the TinyMCE editor in the Sage Notebook, it appears fine. But if I open the cell to change the content, then the Korean characters are all gone and strange characters are shown instead. Perhaps an encoding problem. I was not sure where to ask about this problem. Should I ask to the TinyMCE site? 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Why does import not work?
Dear Robert, On Mar 19, 4:01 am, Robert Bradshaw rober...@math.washington.edu wrote: I would guess you have a circular import issue going on here when you try to put it in the Sage library. Unfortunately, I don't have an easy solution other than trying to be very careful about what you are importing in your files. How can a cycle be avoided? Perhaps I could try to import only the very essentials at the beginning of the file, and to have the remaining import statements only inside the methods. E.g., when I construct a polynomial ring in a method ``foo``, I could import ``from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing`` there, rather than on module level. Does this make sense? Thank you! Simon --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Why does import not work?
On Mar 19, 2009, at 12:04 AM, Simon King wrote: Dear Robert, On Mar 19, 4:01 am, Robert Bradshaw rober...@math.washington.edu wrote: I would guess you have a circular import issue going on here when you try to put it in the Sage library. Unfortunately, I don't have an easy solution other than trying to be very careful about what you are importing in your files. How can a cycle be avoided? Perhaps I could try to import only the very essentials at the beginning of the file, and to have the remaining import statements only inside the methods. E.g., when I construct a polynomial ring in a method ``foo``, I could import ``from sage.rings.polynomial.polynomial_ring_constructor import PolynomialRing`` there, rather than on module level. Yes, you could do that. For example, that you're trying to put these into the sage.rings.polynomial.all module, you can't import anything from sage.rings.polynomial.all (or anything that indirectly imports from there). Currently things are messier than they should be. See, e.g., http://trac.sagemath.org/sage_trac/ticket/4986 - 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Why does import not work?
Dear Robert, On Mar 19, 8:11 am, Robert Bradshaw rober...@math.washington.edu wrote: For example, that you're trying to put these into the sage.rings.polynomial.all module, you can't import anything from sage.rings.polynomial.all Ok, that answers my original question, since I use PolynomialRing in my module. Thank you very much, Simon --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Korean characters in TinyMCE
On Wed, 18 Mar 2009 at 11:00PM -0700, Kwankyu wrote: If I write in Korean and save in the TinyMCE editor in the Sage Notebook, it appears fine. But if I open the cell to change the content, then the Korean characters are all gone and strange characters are shown instead. Perhaps an encoding problem. I was not sure where to ask about this problem. Should I ask to the TinyMCE site? I can confirm this. If I type 안녕하세요! (Hello!), save, and edit, I get ìë íì¸ì! If I save that, it gets displayed the same way, and then if I edit again, I get ìÂÂë ÂíÂÂì¸ìÂÂ! (See https://sagenb.kaist.ac.kr:8066/home/pub/4 to see this in the notebook.) My (wild and uneducated) guess is that this is related to some sort of escaping issue, in the same spirit as #4851. Dan -- --- Dan Drake dr...@kaist.edu - KAIST Department of Mathematical Sciences --- http://mathsci.kaist.ac.kr/~drake signature.asc Description: Digital signature
[sage-support] creating symbolic variables.
This is apparently a very easy question, but I am new to the mathematics
computing environment and it will take me some time to become familiar
with Sage. The question is the following; Are these two expressions
similar?
sage: a,b,c = var('a,b,c')
sage: var('a,b,c')
If not, when should I use one or another?
In the documentation regarding the substitute method and when I checked the
examples I noticed that they show:
sage: x,y,t = var('x,y,t')
I guess this is not necessary because Sage considers by default x as a
symbolic variable, isn't it?
Thanks in advance.
Jose.
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[sage-support] Re: Korean characters in TinyMCE
Hello, the same is with Czech. Seems to be related to http://groups.google.cz/group/sage-support/browse_thread/thread/60a863def66c05a1/ca1626cc03a29bfa?lnk=gstq=accent#ca1626cc03a29bfa and reported on http://trac.sagemath.org/sage_trac/ticket/4956 Robert On 19 Bře, 08:27, Dan Drake dr...@kaist.edu wrote: On Wed, 18 Mar 2009 at 11:00PM -0700, Kwankyu wrote: If I write in Korean and save in the TinyMCE editor in the Sage Notebook, it appears fine. But if I open the cell to change the content, then the Korean characters are all gone and strange characters are shown instead. Perhaps an encoding problem. I was not sure where to ask about this problem. Should I ask to the TinyMCE site? I can confirm this. If I type 안녕하세요! (Hello!), save, and edit, I get 안녕하세요! If I save that, it gets displayed the same way, and then if I edit again, I get 안녕하세요! (Seehttps://sagenb.kaist.ac.kr:8066/home/pub/4to see this in the notebook.) My (wild and uneducated) guess is that this is related to some sort of escaping issue, in the same spirit as #4851. Dan -- --- Dan Drake dr...@kaist.edu - KAIST Department of Mathematical Sciences --- http://mathsci.kaist.ac.kr/~drake signature.asc 1KZobrazitStáhnout --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Korean characters in TinyMCE
On 19 Bře, 07:00, Kwankyu ekwan...@gmail.com wrote: Hi, If I write in Korean and save in the TinyMCE editor in the Sage Notebook, it appears fine. But if I open the cell to change the content, then the Korean characters are all gone and strange characters are shown instead. Perhaps an encoding problem. I was not sure where to ask about this problem. Should I ask to the TinyMCE site? The problem was before integrating TinyMCE. I think that this is problem at Sage. Robert 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: creating symbolic variables.
Hi Jose,
On Thu, Mar 19, 2009 at 7:49 AM, Jose Guzman n...@neurohost.org wrote:
This is apparently a very easy question, but I am new to the mathematics
computing environment and it will take me some time to become familiar
with Sage. The question is the following; Are these two expressions
similar?
sage: a,b,c = var('a,b,c')
sage: var('a,b,c')
If not, when should I use one or another?
Both of the expressions above are more or less the same in that they
produce the same result, i.e. declaring three symbolic variables. But
note these points. If you do
[1]
sage: a,b,c = var(a,b,c)
then it results in what you expect: namely, declaring the three
specified symbolic variables. Now if you do
[2]
sage: var(a,b,c)
(a, b, c)
Sage does the same thing, but this time the three symbolic variables
are printed to your terminal. The last command actually returns a
tuple of three symbolic variables, so it makes sense to do as per [1].
In Python, command [1] technically unpacks the tuple elements and
store them in the variable names to the left of the equal sign. But if
you do as in [2], then the required symbolic variables would have been
declared even if you don't explicitly store the tuple elements: note
this
sage: var(a,b,c)
(a, b, c)
sage: type(a); type(b); type(c)
class 'sage.calculus.calculus.SymbolicVariable'
class 'sage.calculus.calculus.SymbolicVariable'
class 'sage.calculus.calculus.SymbolicVariable'
Also, if you like command [2] because it's less to type on the
keyboard, then by all means do it. And if you don't want to see the
returned tuple of symbolic variables, you can do this:
sage: var(a,b,c);
--
Regards
Minh Van Nguyen
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[sage-support] determinants of matrix polynomials
I want to compute determinants of matrix polynomials, for matrices up to 20 x 20, say. The attached transcript seems to indicate 9 or 10 might be my limit. (Or it's late and I am being stupd?) -- | Sage Version 3.4, Release Date: 2009-03-11 | | Type notebook() for the GUI, and license() for information.| -- # intel mac pro, binary distribution sage: P = graphs.PetersenGraph() sage: P.delete_edge([0,1]) sage: P.degree() [2, 2, 3, 3, 3, 3, 3, 3, 3, 3] sage: P Petersen graph: Graph on 10 vertices ## but P is not the Petersen graph now sage: A = P.am() sage: Id = identity_matrix(10) sage: R.t = QQ[] sage: (t+1)^5 t^5 + 5*t^4 + 10*t^3 + 10*t^2 + 5*t + 1 sage: M = t*Id - A; M [ t 0 0 0 -1 -1 0 0 0 0] [ 0 t -1 0 0 0 -1 0 0 0] [ 0 -1 t -1 0 0 0 -1 0 0] [ 0 0 -1 t -1 0 0 0 -1 0] [-1 0 0 -1 t 0 0 0 0 -1] [-1 0 0 0 0 t 0 -1 -1 0] [ 0 -1 0 0 0 0 t 0 -1 -1] [ 0 0 -1 0 0 -1 0 t 0 -1] [ 0 0 0 -1 0 -1 -1 0 t 0] [ 0 0 0 0 -1 0 -1 -1 0 t] sage: M.det() ## and sage hangs ## but the following worked sage: K =graphs.CompleteGraph(3) sage: B =K.am() sage: Id = identity_matrix(3) sage: (t*Id-B).det() t^3 - 3*t - 2 sage: C = graphs.CubeGraph(3) sage: C 3-Cube: Graph on 8 vertices sage: Id = identity_matrix(8) sage: (t*Id-C.am()).det() t^8 - 12*t^6 + 30*t^4 - 28*t^2 + 9 # and the cycle on 9 vertices hangs --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: determinants of matrix polynomials
On Mar 19, 2009, at 1:17 AM, Chris Godsil wrote: I want to compute determinants of matrix polynomials, for matrices up to 20 x 20, say. The attached transcript seems to indicate 9 or 10 might be my limit. (Or it's late and I am being stupd?) It depends on what ring you're over. sage: M = random_matrix(ZZ, 100); M 100 x 100 dense matrix over Integer Ring sage: time M.det() CPU times: user 0.06 s, sys: 0.00 s, total: 0.07 s Wall time: 0.07 s 227532739129946890993919801650069690831259013161380617147968485792614242 900489259103289021402067670696965272359625204046028722848602428730109991 83429371192981564969154912060350722012918063477112770597042 There isn't optimized code for doing it over QQ[t], so that's why it's really slow. It looks like what you really want is the characteristic polynomial, which on matrices of this size should be virtually instantaneous. sage: P = graphs.PetersenGraph() sage: P.delete_edge([0,1]) sage: A = P.am() sage: A.charpoly() x^10 - 14*x^8 + 65*x^6 - 16*x^5 - 128*x^4 + 72*x^3 + 84*x^2 - 80*x + 16 -- | Sage Version 3.4, Release Date: 2009-03-11 | | Type notebook() for the GUI, and license() for information.| -- # intel mac pro, binary distribution sage: P = graphs.PetersenGraph() sage: P.delete_edge([0,1]) sage: P.degree() [2, 2, 3, 3, 3, 3, 3, 3, 3, 3] sage: P Petersen graph: Graph on 10 vertices ## but P is not the Petersen graph now sage: A = P.am() sage: Id = identity_matrix(10) sage: R.t = QQ[] sage: (t+1)^5 t^5 + 5*t^4 + 10*t^3 + 10*t^2 + 5*t + 1 sage: M = t*Id - A; M [ t 0 0 0 -1 -1 0 0 0 0] [ 0 t -1 0 0 0 -1 0 0 0] [ 0 -1 t -1 0 0 0 -1 0 0] [ 0 0 -1 t -1 0 0 0 -1 0] [-1 0 0 -1 t 0 0 0 0 -1] [-1 0 0 0 0 t 0 -1 -1 0] [ 0 -1 0 0 0 0 t 0 -1 -1] [ 0 0 -1 0 0 -1 0 t 0 -1] [ 0 0 0 -1 0 -1 -1 0 t 0] [ 0 0 0 0 -1 0 -1 -1 0 t] sage: M.det() ## and sage hangs ## but the following worked sage: K =graphs.CompleteGraph(3) sage: B =K.am() sage: Id = identity_matrix(3) sage: (t*Id-B).det() t^3 - 3*t - 2 sage: C = graphs.CubeGraph(3) sage: C 3-Cube: Graph on 8 vertices sage: Id = identity_matrix(8) sage: (t*Id-C.am()).det() t^8 - 12*t^6 + 30*t^4 - 28*t^2 + 9 # and the cycle on 9 vertices hangs --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: determinants of matrix polynomials
Hi Chris, On Thu, Mar 19, 2009 at 8:17 AM, Chris Godsil cgod...@uwaterloo.ca wrote: I want to compute determinants of matrix polynomials, for matrices up to 20 x 20, say. The attached transcript seems to indicate 9 or 10 might be my limit. (Or it's late and I am being stupd?) -- | Sage Version 3.4, Release Date: 2009-03-11 | | Type notebook() for the GUI, and license() for information.| -- # intel mac pro, binary distribution sage: P = graphs.PetersenGraph() sage: P.delete_edge([0,1]) sage: P.degree() [2, 2, 3, 3, 3, 3, 3, 3, 3, 3] sage: P Petersen graph: Graph on 10 vertices ## but P is not the Petersen graph now sage: A = P.am() sage: Id = identity_matrix(10) sage: R.t = QQ[] sage: (t+1)^5 t^5 + 5*t^4 + 10*t^3 + 10*t^2 + 5*t + 1 sage: M = t*Id - A; M [ t 0 0 0 -1 -1 0 0 0 0] [ 0 t -1 0 0 0 -1 0 0 0] [ 0 -1 t -1 0 0 0 -1 0 0] [ 0 0 -1 t -1 0 0 0 -1 0] [-1 0 0 -1 t 0 0 0 0 -1] [-1 0 0 0 0 t 0 -1 -1 0] [ 0 -1 0 0 0 0 t 0 -1 -1] [ 0 0 -1 0 0 -1 0 t 0 -1] [ 0 0 0 -1 0 -1 -1 0 t 0] [ 0 0 0 0 -1 0 -1 -1 0 t] sage: M.det() ## and sage hangs Well, it hangs for a while and then gives me this: sage: M.det() t^10 - 14*t^8 + 65*t^6 - 16*t^5 - 128*t^4 + 72*t^3 + 84*t^2 - 80*t + 16 -- Regards Minh Van Nguyen --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Korean characters in TinyMCE
Hi Robert, Right. Korean texts are not saved properly even in evaluation cells. I experimented on Sage 3.4 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Korean characters in TinyMCE
Hi Dan, I see Ticket #4851 was fixed in Sage 3.3. But I found this problem in Sage 3.4. Also Korean texts even in evaluation cells are not saved properly. So... is someone working on this or is this a new bug? 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: How to set up a macmini as a server?
Check out this thread:
http://groups.google.com/group/sage-support/browse_thread/thread/b6d99cac522a3cd9/6b99c90b85b68d80?lnk=gstq=stan+server#6b99c90b85b68d80
In brief, William's instructions worked for me:
sage: notebook(address=ipaddress,port=8100,secure=True)
then from another computer on your network try to visit the web page
https://ipaddress:8100
That's pretty much it, except for making accounts. To create accounts
you could temporarily do
sage: notebook(address=ipaddress,port=8100,secure=True, accounts=True)
let people make accounts, then do
sage: notebook(address=ipaddress,port=8100,secure=True,accounts=False)
so no new accounts can be created.
I used it on our intranet, where I replaced ipaddress by the network
name of my computer. It works great.
Stan
Calcifer wrote:
Hi,
I have downloaded Sage 3.4 to my MacMini running10.5.6.
When I write notebook(), it starts as expected in a web broswer, but
may not be accessible throu the local network.
if I write the following, I get blank (white) pages both on the
macmini and on the other computer, ie can not access Sage through
either of the computers.
notebook('local_notebook', port=8001, secure=True, address='',
open_viewer=False, accounts=True)
I found the above in one of posts, but don't really understand all of
the expression.
My aim is to be able to access Sage from any computer and that Sage is
automatically starts up after a power failure.
Have a nice day,
T
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[sage-support] Re: Korean characters in TinyMCE
Could this conceivably be a Unicode issue, i.e. that it's not supported by the Sage notebook internally? What file format does worksheet.txt have - just ASCII? That could explain why different character sets, not just one or the other script, are having trouble. - 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Korean characters in TinyMCE
Hello, I put up a patch at #5564 which (along with the patches at #4547 and #5211) fixes all of the issues at #2896, #1477, and #4956 for me. It could use some wider testing though. --Mike --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] bug in region_plot
Hello, this command produces one half of a cirle, not 1/4 as excepted. I think that this is a bug in sage 3.4 Robert region_plot([y0,x0,x^2+y^23], (-3, 3), (-3, 3),plot_points=100,incol='gray').show(aspect_ratio=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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: OS X Clickable application
I must misunderstand something very trivial. I followed the steps described at the release tour of Sage 3.3, except that I replaced 3.3 with 3.4, since I thought I was compiling sage-3.4. Compiling was successful and when I did ./sage -bdist 3.4, I saw that this generated a directory SAGE_ROOT/dist. But, in the directory I have a dmg file and one subdirectory sage-3.4-i386-Darwin, which just looks like another copy of SAGE_ROOT. I don't see any clickable Mac OS X app anywhere, including in the disk image from the dmg file. What am I missing? Oh, btw, I'm using OS X 10.5.6. Thanks in advance. On Mar 18, 9:50 pm, Minh Nguyen nguyenmi...@gmail.com wrote: Hi, On Thu, Mar 19, 2009 at 1:43 AM, Byungchul Cha cha3...@gmail.com wrote: I remember reading something about making a clickable sage application for mac os X. Can I now do such a thing with sage 3.4? If so, where I can find the instruction? The release tour of Sage 3.3 at http://mvngu.wordpress.com/2009/02/23/sage-33-released/ contains instruction on making a clickable Mac OS X app. See especially the instructions under the heading Distribution on that page. If any of the three steps listed under that heading fail for your particular OS X version, please inform me. -- Regards Minh Van Nguyen --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] weird behaviour when selecting a row/column from a matrix
Hi, let me dive straight into my problem wit a simple example: a = identity_matrix(ZZ,2,2) a[0,0] 1 vs. a[:,0] [1] [0] a[:,0][0] (1) So when selecting an element from a matrix by first selecting a row and selecting the wanted element in that new 'row object', I don't get an element from ZZ but a FreeModuleElement. Why is this happening? Is there a way to make my two actions behave like selecting an element from the original matrix? Thanks, Christophe --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: bug in region_plot
ma...@mendelu.cz wrote: Hello, this command produces one half of a cirle, not 1/4 as excepted. I think that this is a bug in sage 3.4 Robert region_plot([y0,x0,x^2+y^23], (-3, 3), (-3, 3),plot_points=100,incol='gray').show(aspect_ratio=1) I get a quarter-circle on my sage 3.4 and on sagenb.org. Can you try on sagenb.org? Also, can you open a fresh worksheet and try the above code, just to make sure it's not a bug with displaying old images? 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Korean characters in TinyMCE
Hello, I used the commands hg_sage.import_patch(http://trac.sagemath.org/sage_trac/raw- attachment/ticket/4547/trac_4547.patch) hg_sage.import_patch(http://trac.sagemath.org/sage_trac/raw- attachment/ticket/5211/trac_5211.patch) hg_sage.import_patch(http://trac.sagemath.org/sage_trac/raw- attachment/ticket/5564/trac_5564-1.patch) hg_sage.import_patch(http://trac.sagemath.org/sage_trac/raw- attachment/ticket/5564/trac_5564-2.patch) but nothing changed. Are these commands correct? Are these commands enough to apply patches? Thank you. Robert. On 19 Bře, 13:15, Mike Hansen mhan...@gmail.com wrote: Hello, I put up a patch at #5564 which (along with the patches at #4547 and #5211) fixes all of the issues at #2896, #1477, and #4956 for me. It could use some wider testing though. --Mike --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Korean characters in TinyMCE
On 19 Bře, 16:55, ma...@mendelu.cz ma...@mendelu.cz wrote: Hello, I used the commands hg_sage.import_patch(http://trac.sagemath.org/sage_trac/raw- attachment/ticket/4547/trac_4547.patch) hg_sage.import_patch(http://trac.sagemath.org/sage_trac/raw- attachment/ticket/5211/trac_5211.patch) hg_sage.import_patch(http://trac.sagemath.org/sage_trac/raw- attachment/ticket/5564/trac_5564-1.patch) hg_sage.import_patch(http://trac.sagemath.org/sage_trac/raw- attachment/ticket/5564/trac_5564-2.patch) but nothing changed. Are these commands correct? Are these commands enough to apply patches? Oops, I forgot build using sage -b After this commands Czech input works for me. Thank you very much for the patches. 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Korean characters in TinyMCE
ma...@mendelu.cz wrote: Hello, I used the commands hg_sage.import_patch(http://trac.sagemath.org/sage_trac/raw- attachment/ticket/4547/trac_4547.patch) hg_sage.import_patch(http://trac.sagemath.org/sage_trac/raw- attachment/ticket/5211/trac_5211.patch) hg_sage.import_patch(http://trac.sagemath.org/sage_trac/raw- attachment/ticket/5564/trac_5564-1.patch) hg_sage.import_patch(http://trac.sagemath.org/sage_trac/raw- attachment/ticket/5564/trac_5564-2.patch) but nothing changed. Are these commands correct? Are these commands enough to apply patches? You also need to rebuild sage. Exit sage and do sage -br Jason Thank you. Robert. On 19 Bře, 13:15, Mike Hansen mhan...@gmail.com wrote: Hello, I put up a patch at #5564 which (along with the patches at #4547 and #5211) fixes all of the issues at #2896, #1477, and #4956 for me. It could use some wider testing though. --Mike --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: OS X Clickable application
On Thu, Mar 19, 2009 at 6:46 AM, Byungchul Cha cha3...@gmail.com wrote: I must misunderstand something very trivial. I followed the steps described at the release tour of Sage 3.3, except that I replaced 3.3 with 3.4, since I thought I was compiling sage-3.4. Compiling was successful and when I did ./sage -bdist 3.4, I saw that this generated a directory SAGE_ROOT/dist. But, in the directory I have a dmg file and one subdirectory sage-3.4-i386-Darwin, which just looks like another copy of SAGE_ROOT. I don't see any clickable Mac OS X app anywhere, including in the disk image from the dmg file. What am I missing? I believe there were some bugs/kinks in the clickable app, so we still aren't making it by default when one does sage -bdist. William Oh, btw, I'm using OS X 10.5.6. Thanks in advance. On Mar 18, 9:50 pm, Minh Nguyen nguyenmi...@gmail.com wrote: Hi, On Thu, Mar 19, 2009 at 1:43 AM, Byungchul Cha cha3...@gmail.com wrote: I remember reading something about making a clickable sage application for mac os X. Can I now do such a thing with sage 3.4? If so, where I can find the instruction? The release tour of Sage 3.3 at http://mvngu.wordpress.com/2009/02/23/sage-33-released/ contains instruction on making a clickable Mac OS X app. See especially the instructions under the heading Distribution on that page. If any of the three steps listed under that heading fail for your particular OS X version, please inform me. -- Regards Minh Van Nguyen -- 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: bug in region_plot
On 19 Mrz., 16:47, Jason Grout jason-s...@creativetrax.com wrote:
ma...@mendelu.cz wrote:
Hello, this command produces one half of a cirle, not 1/4 as excepted.
I think that this is a bug in sage 3.4
Robert
region_plot([y0,x0,x^2+y^23], (-3, 3), (-3,
3),plot_points=100,incol='gray').show(aspect_ratio=1)
I get a quarter-circle on my sage 3.4 and on sagenb.org. Can you try on
sagenb.org?
This works:
sage: var('x,y')
sage: region_plot([y0,x0,x^2+y^23], (x, -3, 3), (y, -3,3))
But if one leaves out the variables, one gets an half circle:
sage: region_plot([y0,x0,x^2+y^23], (-3, 3), (-3,3))
I've written a patch which fixes this:
http://trac.sagemath.org/sage_trac/ticket/5567
cheers,
Wilfried
Also, can you open a fresh worksheet and try the above code, just to
make sure it's not a bug with displaying old images?
Thanks,
Jason
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[sage-support] Re: bug in region_plot
On 19 Bře, 16:47, Jason Grout jason-s...@creativetrax.com wrote: ma...@mendelu.cz wrote: Hello, this command produces one half of a cirle, not 1/4 as excepted. I think that this is a bug in sage 3.4 Robert region_plot([y0,x0,x^2+y^23], (-3, 3), (-3, 3),plot_points=100,incol='gray').show(aspect_ratio=1) I get a quarter-circle on my sage 3.4 and on sagenb.org. Can you try on sagenb.org? strange, I get half-circle on sagenb.org (started new worksheet, published as http://sagenb.org/home/pub/385/ ) Robert Also, can you open a fresh worksheet and try the above code, just to make sure it's not a bug with displaying old images? 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: bug in region_plot
This works:
sage: var('x,y')
sage: region_plot([y0,x0,x^2+y^23], (x, -3, 3), (y, -3,3))
But if one leaves out the variables, one gets an half circle:
sage: region_plot([y0,x0,x^2+y^23], (-3, 3), (-3,3))
I've written a patch which fixes
this:http://trac.sagemath.org/sage_trac/ticket/5567
cheers,
Wilfried
Many thanks, this explains the problem.
Thanks.
Robert.
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[sage-support] how to pull back an ideal by a canonical surjection ?
Dear List,
I'm trying to do some algebraic geometrical / arithmetical computation
with Sage and I find myself stuck on the following dumb problem: if I
have an ideal J of a quotient ring R/I (where R is a polynomial ring
and I some ideal of it), I wish to construct the ideal of R (called
p^{-1}(J) or perhaps even simply I+J) which is obtained by pulling
back J by the canonical map p:R-R/I. This presents no algorithmic
difficulty, since I is given by generators (in R), and J is also given
by generators (in R/I, but they are themselves represented by elements
of R) and it is just a question of taking the union of these lists of
generators (seeing those of J in R/I as arbitrary representatives in
R) to obtain the desired idea. Unfortunately, this doesn't seem to
work (probably because Sage doesn't know how to handle the canonical
surjection specially?):
vega david /usr/local/src/sage-3.4 $ ./sage
--
| Sage Version 3.4, Release Date: 2009-03-11 |
| Type notebook() for the GUI, and license() for information.|
--
sage: R.x,y = QQ['x','y']
sage: I = Ideal(y^2 - x^3 - x)
sage: Rq = R.quotient(I)
sage: p = R.hom(Rq)
sage: J = Ideal(p(y)-1)
sage: J
Ideal (ybar - 1) of Quotient of Multivariate Polynomial Ring in x, y over
Rational Field by the ideal (-x^3 + y^2 - x)
sage: p.inverse_image(J)
---
NotImplementedError Traceback (most recent call last)
/usr/src/local/sage-3.4/ipython console in module()
/usr/src/local/sage-3.4/local/lib/python2.5/site-packages/sage/rings/morphism.so
in sage.rings.morphism.RingHomomorphism.inverse_image
(sage/rings/morphism.c:3480)()
NotImplementedError:
sage: whatiwantedwasthis = I + Ideal(y-1)
sage: whatiwantedwasthis
Ideal (-x^3 + y^2 - x, y - 1) of Multivariate Polynomial Ring in x, y over
Rational Field
sage: p(whatiwantedwasthis)
Ideal (0, ybar - 1) of Quotient of Multivariate Polynomial Ring in x, y over
Rational Field by the ideal (-x^3 + y^2 - x)
sage: p(whatiwantedwasthis) == J
True
By comparison, Macaulay2 does this:
vega david ~ $ /opt/Macaulay2-1.2-r8438/bin/M2
Macaulay 2, version 1.2
with packages: Elimination, IntegralClosure, LLLBases, PrimaryDecomposition,
ReesAlgebra, SchurRings, TangentCone
i1 : R = QQ[x,y]
o1 = R
o1 : PolynomialRing
i2 : I = ideal(y^2-x^3-x)
32
o2 = ideal(- x + y - x)
o2 : Ideal of R
i3 : Rq = R/I
o3 = Rq
o3 : QuotientRing
i4 : p = map(Rq,R,matrix{{x,y}})
o4 = map(Rq,R,{x, y})
o4 : RingMap Rq --- R
i5 : J = ideal(y-1)
o5 = ideal(y - 1)
o5 : Ideal of Rq
i6 : preimage(p,J)
3
o6 = ideal (y - 1, x + x - 1)
o6 : Ideal of R
i7 : use R; whatiwantedwasthis = I + ideal(y-1)
32
o8 = ideal (- x + y - x, y - 1)
o8 : Ideal of R
i9 : o6 == whatiwantedwasthis
o9 = true
i10 : p(whatiwantedwasthis)
o10 = ideal (0, y - 1)
o10 : Ideal of Rq
i11 : p(whatiwantedwasthis) == J
o11 = true
(Unfortunately, I can't do my computations in Macaulay2 because I need
polynomial rings over number fields - the above example is in Q - and
it can't handle them.)
So, is there a way in Sage to pull back an ideal by a canonical map?
--
David A. Madore
( http://www.madore.org/~david/ )
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[sage-support] Testing whether a function is always positive
Hi all, I'm working on a project, and my professor suggest I post a question here. I'm trying to use programs such as Mathematica, Maple and Sage to test whether a function is always positive. Maple has an is command, which can be used to test some properties. Sometimes it is sufficient, other times it fails. Does Sage have anything like an is command? Is there any other way to test if a function is always positve/negative? 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Testing whether a function is always positive
Do you mean something like bool(x^6-1) Or you can use maxima inside sage and the command is http://maxima.sourceforge.net/docs/manual/en/maxima_5.html#Item_003a-is I think that in general you can expect poor results in any computer algebra system (like you write about Maple). Robert On 19 Bře, 15:51, PaulBurk paulburkan...@gmail.com wrote: Hi all, I'm working on a project, and my professor suggest I post a question here. I'm trying to use programs such as Mathematica, Maple and Sage to test whether a function is always positive. Maple has an is command, which can be used to test some properties. Sometimes it is sufficient, other times it fails. Does Sage have anything like an is command? Is there any other way to test if a function is always positve/negative? 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: OS X Clickable application
On Mar 19, 9:35 am, William Stein wst...@gmail.com wrote: On Thu, Mar 19, 2009 at 6:46 AM, Byungchul Cha cha3...@gmail.com wrote: I must misunderstand something very trivial. I followed the steps described at the release tour of Sage 3.3, except that I replaced 3.3 with 3.4, since I thought I was compiling sage-3.4. Compiling was successful and when I did ./sage -bdist 3.4, I saw that this generated a directory SAGE_ROOT/dist. But, in the directory I have a dmg file and one subdirectory sage-3.4-i386-Darwin, which just looks like another copy of SAGE_ROOT. I don't see any clickable Mac OS X app anywhere, including in the disk image from the dmg file. What am I missing? I believe there were some bugs/kinks in the clickable app, so we still aren't making it by default when one does sage -bdist. William Run SAGE_APP_BUNDLE=yes; export SAGE_APP_BUNDLE before -bdisting and there App bundle will be created. As William mentioned due to bugs this is not done per default at the moment. Cheers, Michael --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: SSE4_1 errors when running sage 3.4
Hi, I built sage from source and ran 'make test' on it. It failed on sage -t devel/sage/sage/plot/plot.py sage -t devel/sage/sage/symbolic/function.pyx sage -t devel/sage/sage/rings/polynomial/multi_polynomial.pyx sage -t devel/sage/sage/functions/constants.py though the build documentation suggested that it was normal to fail on a couple tests? When I launch the version I compiled from source, it didn't give me any warning about instruction sets. It appears to function exactly the same as the binary I downloaded, once I removed the sage-flags.txt file. So it seems that there is nothing wrong with the pre-built version, though someone might want to look into why it claims to require sse4_1 when it does not appear to need them (possibly it was compiled on a machine with sse4 so it automatically assumes it is needed?). Perhaps sse4 doesn't need to be listed in sage-flags.txt? As for William Stein's comment, I watched memory usage as it tried to compute pi(10^10), and it didn't rise noticeably before giving the seg fault (it also only took a moment). Even if it is a memory issue, doesn't sage have a more graceful and informative way to fail? I wonder how pi(x) is computed in sage, it it is simply referencing a pre-computed table of primes then perhaps the seg fault is an indication that it went past the end of the table? I looked at the entry in the tracker, what does prime_pi(k,40) do? I thought that prime_pi was a function of a single variable, and when I tried using it that way in sage it threw an error. Thank you both for your help, - Ryan On Mar 18, 3:20 pm, Johan Oudinet johan.oudi...@gmail.com wrote: On Wed, Mar 18, 2009 at 4:20 PM, bix...@gmail.com bix...@gmail.com wrote: Hi, After using version 3 for over a year, it finally occured to me I should upgrade. When trying to start version 3.4 I get: -- | Sage Version 3.4, Release Date: 2009-03-11 | | Type notebook() for the GUI, and license() for information. | -- ** WARNING! This Sage install was built on a machine that supports instructions that are not available on this computer. Sage will likely fail with ILLEGAL INSTRUCTION errors! The following processor flags were on the build machine but are not on this computer: sse4_1 Emailhttp://groups.google.com/group/sage-supportfor help. To remove this warning and make Sage start, just delete /home/bixbyr/Desktop/sage-3.4-linux-Ubuntu_8.10-i686-Linux/local/ lib/sage-flags.txt ** I tried removing this file to see if sage will run correctly, it doesn't seem to. For a quick stress test I did sage: prime_pi(10^10) ... and got back /home/bixbyr/Desktop/sage-3.4-linux-Ubuntu_8.10-i686-Linux/local/bin/ sage-sage: line 197: 8689 Segmentation fault sage-ipython $@ - i It returns correctly for prime_pi(10^9), so although it's possible that the two errors are unrelated, that seems a strange way to fail if the issue were related to insufficient memory. I downloaded sage-3.4-linux-Ubuntu_8.10-i686-Linux.tar.gz from the University of Washington mirror. I'm running ubuntu 8.10, kernel version 2.6.27-11-generic. I have 4gb of ram, though running a 32 bit kernel effectively limits me to ~3.2 gb. Since sse4 is a cpu instruction set (from what I understand), here it the output for cat / proc/cpuinfo: processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz stepping : 11 cpu MHz : 1600.000 cache size : 4096 KB physical id : 0 siblings : 4 core id : 0 cpu cores : 4 apicid : 0 initial apicid : 0 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc arch_perfmon pebs bts pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr lahf_lm bogomips : 4799.97 clflush size : 64 power management: ( ... it then lists 3 more processors with the same information) Although not the newest processor, it seems like this should be recent enough to run sage. I also tried installing the new version on my laptop, another ubuntu 8.10 system this time with a core 2 duo processor, and got the exact same error. Any thoughts? Thanks a lot, Have you tried to build Sage from sources? If you also get the same error, it will
[sage-support] Re: bug in region_plot
Wilfried_Huss wrote:
On 19 Mrz., 16:47, Jason Grout jason-s...@creativetrax.com wrote:
ma...@mendelu.cz wrote:
Hello, this command produces one half of a cirle, not 1/4 as excepted.
I think that this is a bug in sage 3.4
Robert
region_plot([y0,x0,x^2+y^23], (-3, 3), (-3,
3),plot_points=100,incol='gray').show(aspect_ratio=1)
I get a quarter-circle on my sage 3.4 and on sagenb.org. Can you try on
sagenb.org?
This works:
sage: var('x,y')
sage: region_plot([y0,x0,x^2+y^23], (x, -3, 3), (y, -3,3))
But if one leaves out the variables, one gets an half circle:
sage: region_plot([y0,x0,x^2+y^23], (-3, 3), (-3,3))
I've written a patch which fixes this:
http://trac.sagemath.org/sage_trac/ticket/5567
Ah, yes, good catch. For those that want to know, Sage was interpreting
the first two constraints as functions of one variable, so when it
plugged in two numbers, Sage behaved as though you had typed x0, x0.
When I did my example, I explicitly put in the variable names (it's a
good habit to be explicit in plotting), so I got the right plot.
There should be a standard function that takes a tuple of functions and
returns a list of variables for all the functions. This is used all
over the plotting code, the fast_callable code, now this code, etc.
Basically, there should be a function that, treating a tuple of
functions as a vector-valued function, returns the variables used in the
vector-valued function.
Also, I wonder why fast_float is not used? It could drastically speed
up plots. You could just replace the lines like:
s = symbolic_expression(f.rhs() - f.lhs()).function(*variables)
with
s = fast_float(f.rhs() - f.lhs(), *vars)
and you'd probably see at least an order of magnitude speedup. (make
sure to do from sage.ext.fast_eval import fast_float first).
Jason
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[sage-support] Re: how to pull back an ideal by a canonical surjection ?
On Thursday 19 March 2009, David Madore wrote:
Dear List,
I'm trying to do some algebraic geometrical / arithmetical computation
with Sage and I find myself stuck on the following dumb problem: if I
have an ideal J of a quotient ring R/I (where R is a polynomial ring
and I some ideal of it), I wish to construct the ideal of R (called
p^{-1}(J) or perhaps even simply I+J) which is obtained by pulling
back J by the canonical map p:R-R/I. This presents no algorithmic
difficulty, since I is given by generators (in R), and J is also given
by generators (in R/I, but they are themselves represented by elements
of R) and it is just a question of taking the union of these lists of
generators (seeing those of J in R/I as arbitrary representatives in
R) to obtain the desired idea. Unfortunately, this doesn't seem to
work (probably because Sage doesn't know how to handle the canonical
surjection specially?):
vega david /usr/local/src/sage-3.4 $ ./sage
--
| Sage Version 3.4, Release Date: 2009-03-11 |
| Type notebook() for the GUI, and license() for information.|
--
sage: R.x,y = QQ['x','y']
sage: I = Ideal(y^2 - x^3 - x)
sage: Rq = R.quotient(I)
sage: p = R.hom(Rq)
sage: J = Ideal(p(y)-1)
sage: J
Ideal (ybar - 1) of Quotient of Multivariate Polynomial Ring in x, y over
Rational Field by the ideal (-x^3 + y^2 - x) sage: p.inverse_image(J)
---
NotImplementedError Traceback (most recent call last)
/usr/src/local/sage-3.4/ipython console in module()
/usr/src/local/sage-3.4/local/lib/python2.5/site-packages/sage/rings/morphi
sm.so in sage.rings.morphism.RingHomomorphism.inverse_image
(sage/rings/morphism.c:3480)()
NotImplementedError:
sage: whatiwantedwasthis = I + Ideal(y-1)
sage: whatiwantedwasthis
Ideal (-x^3 + y^2 - x, y - 1) of Multivariate Polynomial Ring in x, y over
Rational Field sage: p(whatiwantedwasthis)
Ideal (0, ybar - 1) of Quotient of Multivariate Polynomial Ring in x, y
over Rational Field by the ideal (-x^3 + y^2 - x) sage:
p(whatiwantedwasthis) == J
True
By comparison, Macaulay2 does this:
vega david ~ $ /opt/Macaulay2-1.2-r8438/bin/M2
Macaulay 2, version 1.2
with packages: Elimination, IntegralClosure, LLLBases,
PrimaryDecomposition, ReesAlgebra, SchurRings, TangentCone
i1 : R = QQ[x,y]
o1 = R
o1 : PolynomialRing
i2 : I = ideal(y^2-x^3-x)
32
o2 = ideal(- x + y - x)
o2 : Ideal of R
i3 : Rq = R/I
o3 = Rq
o3 : QuotientRing
i4 : p = map(Rq,R,matrix{{x,y}})
o4 = map(Rq,R,{x, y})
o4 : RingMap Rq --- R
i5 : J = ideal(y-1)
o5 = ideal(y - 1)
o5 : Ideal of Rq
i6 : preimage(p,J)
3
o6 = ideal (y - 1, x + x - 1)
o6 : Ideal of R
i7 : use R; whatiwantedwasthis = I + ideal(y-1)
32
o8 = ideal (- x + y - x, y - 1)
o8 : Ideal of R
i9 : o6 == whatiwantedwasthis
o9 = true
i10 : p(whatiwantedwasthis)
o10 = ideal (0, y - 1)
o10 : Ideal of Rq
i11 : p(whatiwantedwasthis) == J
o11 = true
(Unfortunately, I can't do my computations in Macaulay2 because I need
polynomial rings over number fields - the above example is in Q - and
it can't handle them.)
So, is there a way in Sage to pull back an ideal by a canonical map?
Quotient rings are in a particularly bad shape in Sage, here's a hack:
sage: R.x,y = QQ['x','y']
sage: I = Ideal(y^2 - x^3 - x)
sage: Q = R.quotient(I)
sage: p = R.hom(Q)
sage: J = Ideal(p(y)-1)
sage: J
Ideal (ybar - 1) of Quotient of Multivariate Polynomial Ring in x, y over
Rational Field by the ideal (-x^3 + y^2 - x)
sage: I2 = Ideal([f._QuotientRingElement__rep for f in J.gens()]) + I
sage: I2
Ideal (y - 1, -x^3 + y^2 - x) of Multivariate Polynomial Ring in x, y over
Rational Field
sage: I2.groebner_basis()
[x^3 + x - 1, y - 1]
that should be what you want. However, f._QuotientRingElement__rep is quite
evil because it uses the internal representation.
I'd actually give it a shot to implement the NotImplementedError above but I'm
unsure where the implementation belongs:
Not sure whether I should just patch RingHomomorphism_coercion:add a bunch of
type checks and then do something like the above if they pass and raise
NotImplementedError otherwise?
Cheers,
Martin
--
name: Martin Albrecht
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_jab: martinralbre...@jabber.ccc.de
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[sage-support] Re: creating symbolic variables.
On Thu, Mar 19, 2009 at 1:01 AM, Minh Nguyen nguyenmi...@gmail.com wrote:
Hi Jose,
On Thu, Mar 19, 2009 at 7:49 AM, Jose Guzman n...@neurohost.org wrote:
This is apparently a very easy question, but I am new to the mathematics
computing environment and it will take me some time to become familiar
with Sage. The question is the following; Are these two expressions
similar?
sage: a,b,c = var('a,b,c')
sage: var('a,b,c')
If not, when should I use one or another?
Just another point. Using the above two is equivalent on the command
line or in .sage scripts. The function var uses a Cython hack to
inject a,b,c into the globals() namespace. In some cases of Sage
library code (.py files) it is *not* equivalent in that doing
var('a,b,c') will make the symbolic variables somewhere, but a,b,c
might not be defined in the current scope.
William
Both of the expressions above are more or less the same in that they
produce the same result, i.e. declaring three symbolic variables. But
note these points. If you do
[1]
sage: a,b,c = var(a,b,c)
then it results in what you expect: namely, declaring the three
specified symbolic variables. Now if you do
[2]
sage: var(a,b,c)
(a, b, c)
Sage does the same thing, but this time the three symbolic variables
are printed to your terminal. The last command actually returns a
tuple of three symbolic variables, so it makes sense to do as per [1].
In Python, command [1] technically unpacks the tuple elements and
store them in the variable names to the left of the equal sign. But if
you do as in [2], then the required symbolic variables would have been
declared even if you don't explicitly store the tuple elements: note
this
sage: var(a,b,c)
(a, b, c)
sage: type(a); type(b); type(c)
class 'sage.calculus.calculus.SymbolicVariable'
class 'sage.calculus.calculus.SymbolicVariable'
class 'sage.calculus.calculus.SymbolicVariable'
Also, if you like command [2] because it's less to type on the
keyboard, then by all means do it. And if you don't want to see the
returned tuple of symbolic variables, you can do this:
sage: var(a,b,c);
--
Regards
Minh Van Nguyen
--
William Stein
Associate Professor of Mathematics
University of Washington
http://wstein.org
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[sage-support] Re: bug in region_plot
Jason Grout wrote:
Wilfried_Huss wrote:
On 19 Mrz., 16:47, Jason Grout jason-s...@creativetrax.com wrote:
ma...@mendelu.cz wrote:
Hello, this command produces one half of a cirle, not 1/4 as excepted.
I think that this is a bug in sage 3.4
Robert
region_plot([y0,x0,x^2+y^23], (-3, 3), (-3,
3),plot_points=100,incol='gray').show(aspect_ratio=1)
I get a quarter-circle on my sage 3.4 and on sagenb.org. Can you try on
sagenb.org?
This works:
sage: var('x,y')
sage: region_plot([y0,x0,x^2+y^23], (x, -3, 3), (y, -3,3))
But if one leaves out the variables, one gets an half circle:
sage: region_plot([y0,x0,x^2+y^23], (-3, 3), (-3,3))
I've written a patch which fixes this:
http://trac.sagemath.org/sage_trac/ticket/5567
Ah, yes, good catch. For those that want to know, Sage was interpreting
the first two constraints as functions of one variable, so when it
plugged in two numbers, Sage behaved as though you had typed x0, x0.
When I did my example, I explicitly put in the variable names (it's a
good habit to be explicit in plotting), so I got the right plot.
There should be a standard function that takes a tuple of functions and
returns a list of variables for all the functions. This is used all
over the plotting code, the fast_callable code, now this code, etc.
Basically, there should be a function that, treating a tuple of
functions as a vector-valued function, returns the variables used in the
vector-valued function.
Also, I wonder why fast_float is not used? It could drastically speed
up plots. You could just replace the lines like:
s = symbolic_expression(f.rhs() - f.lhs()).function(*variables)
with
s = fast_float(f.rhs() - f.lhs(), *vars)
and you'd probably see at least an order of magnitude speedup. (make
sure to do from sage.ext.fast_eval import fast_float first).
Actually, I believe that the call to setup_eval_on_grid automatically
does the call to fast_float, so it's probably already happening and we
don't have to worry about anything.
In fact, I think the root of the problem is in
plot/plot3d/parametric_plot3d.py in the adapt_to_callable function (this
is called by setup_for_eval_on_grid, which is in turn called by
region_plot). Observe (and please pardon my debugging in public :)
sage: from sage.plot.plot3d.parametric_plot3d import adapt_to_callable
sage: var('x,y')
(x, y)
sage: funcs = [x,y]
sage: adapt_to_callable(funcs,2)
((sage.ext.interpreters.wrapper_rdf.Wrapper_rdf object at 0xa9b1d9c,
sage.ext.interpreters.wrapper_rdf.Wrapper_rdf object at 0xa9d916c),
(y, x))
First of all, why in the world are the arguments y, then x? I thought
the convention was alphabetical ordering if an ordering wasn't specified.
Well, the problem is in this line of adapt_to_callable:
tuple(sorted(set(sum( [z.variables() for z in f], ()) )))
Note:
sage: sorted(set(sum([z.variables() for z in funcs],(
[y, x]
and even
sage: sorted(list(set(sum([z.variables() for z in funcs],()
[y, x]
For some reason, sorting the list [y,x] doesn't make it [x,y]:
sage: sorted([y,x])
[y, x]
There seem to be other problems too:
sage: funcs=[x,y,1]
sage: adapt_to_callable(funcs,2)
---
TypeError Traceback (most recent call last)
/home/jason/.sage/temp/littleone/16993/_home_jason__sage_init_sage_0.py
in module()
/home/jason/sage/local/lib/python2.5/site-packages/sage/plot/plot3d/parametric_plot3d.pyc
in adapt_to_callable(f, nargs)
620 except TypeError:
621 vars = ()
-- 622 f = [fast_float_constant(x) for x in f]
623
624 if nargs is not None and len(vars) != nargs:
/home/jason/sage/local/lib/python2.5/site-packages/sage/ext/fast_eval.so
in sage.ext.fast_eval.fast_float_constant (sage/ext/fast_eval.c:6827)()
/home/jason/sage/local/lib/python2.5/site-packages/sage/ext/fast_eval.so
in sage.ext.fast_eval.FastDoubleFunc.__init__ (sage/ext/fast_eval.c:2781)()
TypeError: a float is required
This comes from assuming that if any of the functions doesn't have a
.variables() method, then *all* of the functions must be constants.
That seems a bit silly...
So I think it not a coincidence that this function has no doctests. I
think this is yet another example of code that doesn't have doctests
that (not surprisingly) is broken.
Wilfried, can you take a look at this function (adapt_to_callable)? I
think fixing it will fix probably lots of other bugs as well, since it
is called from lots of plotting code.
Thanks,
Jason
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[sage-support] Re: SSE4_1 errors when running sage 3.4
On Thu, Mar 19, 2009 at 10:10 AM, bix...@gmail.com bix...@gmail.com wrote: Hi, I built sage from source and ran 'make test' on it. It failed on sage -t devel/sage/sage/plot/plot.py sage -t devel/sage/sage/symbolic/function.pyx sage -t devel/sage/sage/rings/polynomial/multi_polynomial.pyx sage -t devel/sage/sage/functions/constants.py though the build documentation suggested that it was normal to fail on a couple tests? When I launch the version I compiled from source, it didn't give me any warning about instruction sets. It appears to function exactly the same as the binary I downloaded, once I removed the sage-flags.txt file. So it seems that there is nothing wrong with the pre-built version, though someone might want to look into why it claims to require sse4_1 when it does not appear to need them (possibly it was compiled on a machine with sse4 so it automatically assumes it is needed? That's true. ). Perhaps sse4 doesn't need to be listed in sage-flags.txt? I think that is true. In fact, I posted a patch to remove ssse4 from the flag list. As for William Stein's comment, I watched memory usage as it tried to compute pi(10^10), and it didn't rise noticeably before giving the seg fault (it also only took a moment). Even if it is a memory issue, doesn't sage have a more graceful and informative way to fail? One would hope. I wonder how pi(x) is computed in sage, it it is simply referencing a pre-computed table of primes then perhaps the seg fault is an indication that it went past the end of the table? No -- in sage = 3.4 it uses the PARI C library to *enumerate* all primes up to x. I looked at the entry in the tracker, what does prime_pi(k,40) do? I thought that prime_pi was a function of a single variable, and when I tried using it that way in sage it threw an error. Thank you both for your help, - Ryan On Mar 18, 3:20 pm, Johan Oudinet johan.oudi...@gmail.com wrote: On Wed, Mar 18, 2009 at 4:20 PM, bix...@gmail.com bix...@gmail.com wrote: Hi, After using version 3 for over a year, it finally occured to me I should upgrade. When trying to start version 3.4 I get: -- | Sage Version 3.4, Release Date: 2009-03-11 | | Type notebook() for the GUI, and license() for information. | -- ** WARNING! This Sage install was built on a machine that supports instructions that are not available on this computer. Sage will likely fail with ILLEGAL INSTRUCTION errors! The following processor flags were on the build machine but are not on this computer: sse4_1 Emailhttp://groups.google.com/group/sage-supportfor help. To remove this warning and make Sage start, just delete /home/bixbyr/Desktop/sage-3.4-linux-Ubuntu_8.10-i686-Linux/local/ lib/sage-flags.txt ** I tried removing this file to see if sage will run correctly, it doesn't seem to. For a quick stress test I did sage: prime_pi(10^10) ... and got back /home/bixbyr/Desktop/sage-3.4-linux-Ubuntu_8.10-i686-Linux/local/bin/ sage-sage: line 197: 8689 Segmentation fault sage-ipython $@ - i It returns correctly for prime_pi(10^9), so although it's possible that the two errors are unrelated, that seems a strange way to fail if the issue were related to insufficient memory. I downloaded sage-3.4-linux-Ubuntu_8.10-i686-Linux.tar.gz from the University of Washington mirror. I'm running ubuntu 8.10, kernel version 2.6.27-11-generic. I have 4gb of ram, though running a 32 bit kernel effectively limits me to ~3.2 gb. Since sse4 is a cpu instruction set (from what I understand), here it the output for cat / proc/cpuinfo: processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz stepping : 11 cpu MHz : 1600.000 cache size : 4096 KB physical id : 0 siblings : 4 core id : 0 cpu cores : 4 apicid : 0 initial apicid : 0 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc arch_perfmon pebs bts pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr lahf_lm bogomips : 4799.97 clflush size : 64 power management: ( ... it then lists 3 more processors with the same information) Although not the newest processor, it seems like this should
[sage-support] Re: Testing whether a function is always positive
On Mar 19, 7:51 am, PaulBurk paulburkan...@gmail.com wrote: Hi all, I'm working on a project, and my professor suggest I post a question here. I'm trying to use programs such as Mathematica, Maple and Sage to test whether a function is always positive. Maple has an is command, which can be used to test some properties. Sometimes it is sufficient, other times it fails. Does Sage have anything like an is command? Is there any other way to test if a function is always positve/negative? What sort of function? With one argument or multiple arguments? For arbitrary functions (involving trig, exponents, etc.), I'm pretty sure that it's provably impossible to always decide whether a function is always positive, so the best any system can do is apply some heuristics that work for some functions but not others. For univariate or multivariate polynomials (with rational coefficients), it's always possible in theory to determine whether a function is positive everywhere, although I don't know of a method that's usable in practice if there's more than a few variables. Carl --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: creating symbolic variables.
Jose Guzman wrote:
This is apparently a very easy question, but I am new to the mathematics
computing environment and it will take me some time to become familiar
with Sage. The question is the following; Are these two expressions
similar?
sage: a,b,c = var('a,b,c')
sage: var('a,b,c')
If not, when should I use one or another?
In the documentation regarding the substitute method and when I checked the
examples I noticed that they show:
sage: x,y,t = var('x,y,t')
I guess this is not necessary because Sage considers by default x as a
symbolic variable, isn't it?
Thanks in advance.
Jose.
Ok, thank you both for your nice explanations. In my case I will
substitute the 'a' and 'b' value setting the equation and evaluate the
results algebraically in terms of x and other symbolic variable. I will
probably give you examples once I became more familiar with Sage.
Regards!
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[sage-support] Error message installing sage 3.4 on G4 iBook
Dear friends, (Sorry for my bad english) I'm trying to install sage 3.4 on a G4 iBook with Mac OS X 10.5.6. I download sage-3.4-PowerPC-OSX10.5-PowerMacintosh-Darwin.dmg without problems. Then I follow README.txt and I copy the sage fonder to the / Applications folder without problems. But, after doing double click on the sage icon, I get the following error on the Terminal: --- Last login: Thu Mar 19 22:21:10 on console /Applications/sage/sage ; exit; Macario:~ jvarona$ /Applications/sage/sage ; exit; -- | Sage Version 3.4, Release Date: 2009-03-11 | | 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. /Applications/sage/local/bin/sage-sage: line 197: 257 Illegal instruction sage-ipython $@ -i logout [Proceso completado] --- What happens? I cannot to use sage. What to do? Thanks in advance, Juan Luis --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Error message installing sage 3.4 on G4 iBook
On Thu, Mar 19, 2009 at 3:58 PM, jlvm juanluis.var...@gmail.com wrote: Dear friends, (Sorry for my bad english) I'm trying to install sage 3.4 on a G4 iBook with Mac OS X 10.5.6. I download sage-3.4-PowerPC-OSX10.5-PowerMacintosh-Darwin.dmg without problems. Then I follow README.txt and I copy the sage fonder to the / Applications folder without problems. But, after doing double click on the sage icon, I get the following error on the Terminal: --- Last login: Thu Mar 19 22:21:10 on console /Applications/sage/sage ; exit; Macario:~ jvarona$ /Applications/sage/sage ; exit; -- | Sage Version 3.4, Release Date: 2009-03-11 | | 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. /Applications/sage/local/bin/sage-sage: line 197: 257 Illegal instruction sage-ipython $@ -i logout [Proceso completado] --- What happens? I cannot to use sage. What to do? If you have a recent version of XCode installed then you can build from source. 1. Get the sage-3.4.tar file here: http://sagemath.org/src/ 2. Extract it (possibly by double clicking on it). 3. Using terminal, change into the sage-3.4 directory, and type $ make This will take a couple of hours, and will likely work fine so long as you have an xcode that is from at least about 2007 or newer. 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Error message installing sage 3.4 on G4 iBook
On Thu, Mar 19, 2009 at 11:20 PM, William Stein wst...@gmail.com wrote: On Thu, Mar 19, 2009 at 3:58 PM, jlvm juanluis.var...@gmail.com wrote: Dear friends, (Sorry for my bad english) I'm trying to install sage 3.4 on a G4 iBook with Mac OS X 10.5.6. I download sage-3.4-PowerPC-OSX10.5-PowerMacintosh-Darwin.dmg without problems. Then I follow README.txt and I copy the sage fonder to the / Applications folder without problems. But, after doing double click on the sage icon, I get the following error on the Terminal: SNIP What happens? I cannot to use sage. What to do? If you have a recent version of XCode installed then you can build from source. 1. Get the sage-3.4.tar file here: http://sagemath.org/src/ If download speed is one of your concerns, you might want to consider downloading Sage from a mirror. Here's a list of available mirrors: http://www.sagemath.org/download-linux.html 2. Extract it (possibly by double clicking on it). 3. Using terminal, change into the sage-3.4 directory, and type $ make This will take a couple of hours, and will likely work fine so long as you have an xcode that is from at least about 2007 or newer. William -- Regards Minh Van Nguyen --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Korean characters in TinyMCE
Hi Jason, Korean input works wonderfully with these patches. Thank you! 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Korean characters in TinyMCE
Hi Mike, Korean input works wonderfully with these patches. Thank you for your nice work! 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] resetting vertex labels
Suppose G is a DiGraph. Is there a way to change the vertex labels of
G so that they are shown when G.show() is called? The method,
G.set_vertex() does not seem to do that.
Sample code
sage: G = DiGraph({1:{2: 2}, 2:{1:1}})
sage: G.show()
sage: G.set_vertex(1,4)
sage: G.show() # -- there is no change
What I am really after is this: I have a collection of integers, one
for each vertex. Over time the integers change. I would like to show
the graph with vertices labeled by these integers. Best of all would
be to do this via @interact.
Thanks,
Dave
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[sage-support] showing graphs with multiple edges
Hi,
I was a bit surprised by the difference exhibited below:
sage: G = DiGraph({1:{2: 2}, 2:{1:1}})
sage: G.show()
sage: DiGraph(G.laplacian_matrix()).show()
The latter draws multiple edges.
Dave
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[sage-support] Error when running Notebook: Error showing url: There was an error launching the default action command associated with this location
I got the following error when running sage -notebook ** ** * Open your web browser to http://localhost:8000 * ** ** 2009-03-19 17:33:51-0700 [-] Log opened. 2009-03-19 17:33:51-0700 [-] twistd 8.1.0 (/usr/local/sage-3.4/local/ bin/python 2.5.2) starting up 2009-03-19 17:33:51-0700 [-] reactor class: class 'twisted.internet.selectreactor.SelectReactor' 2009-03-19 17:33:51-0700 [-] twisted.web2.channel.http.HTTPFactory starting on 8000 2009-03-19 17:33:51-0700 [-] Starting factory twisted.web2.channel.http.HTTPFactory instance at 0x8ca724c Error showing url: There was an error launching the default action command associated with this location. If after that, in the url of firefox I type http://localhost:8000 it begins to work. Any idea why it does not work? ---Alex Lara --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: showing graphs with multiple edges
davidp wrote:
Hi,
I was a bit surprised by the difference exhibited below:
sage: G = DiGraph({1:{2: 2}, 2:{1:1}})
sage: G.show()
I'm surprised by the output of this. There are clearly two edges in the
graph: 1-2 and 2-1, but only one edge is shown.
sage: DiGraph(G.laplacian_matrix()).show()
The Laplacian matrix has nonzero entries indicating edges from each
vertex to each other vertex, so why do you find it surprising that there
are two edges?
sage: H=DiGraph(G.laplacian_matrix())
sage: H.edges()
[(0, 0, 1), (0, 1, -1), (1, 0, -1), (1, 1, 1)]
I find it surprising that arrowheads don't appear in the following, though:
sage: DiGraph(G.laplacian_matrix()).show()
Thanks,
Jason
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[sage-support] Re: showing graphs with multiple edges
Sorry. I was not being clear. I was surprised by the fact that
*only* the latter shows multiple edges.
I am also surprised that arrowheads don't appear with multiple edges.
This is especially a problem with weighted digraphs.
(By the way, it probably would have been better for me to have written
sage: G = DiGraph({1:{2: 2}, 2:{1:1}}, weighted=True)
so that the Laplacian comes out correctly. However, this doesn't help
with my problem.)
Dave
On Mar 19, 6:01 pm, Jason Grout jason-s...@creativetrax.com wrote:
davidp wrote:
Hi,
I was a bit surprised by the difference exhibited below:
sage: G = DiGraph({1:{2: 2}, 2:{1:1}})
sage: G.show()
I'm surprised by the output of this. There are clearly two edges in the
graph: 1-2 and 2-1, but only one edge is shown.
sage: DiGraph(G.laplacian_matrix()).show()
The Laplacian matrix has nonzero entries indicating edges from each
vertex to each other vertex, so why do you find it surprising that there
are two edges?
sage: H=DiGraph(G.laplacian_matrix())
sage: H.edges()
[(0, 0, 1), (0, 1, -1), (1, 0, -1), (1, 1, 1)]
I find it surprising that arrowheads don't appear in the following, though:
sage: DiGraph(G.laplacian_matrix()).show()
Thanks,
Jason
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[sage-support] Re: determinants of matrix polynomials
Thanks for your comments so far. Please note that I want to compute determinants of matrices whose entries are polynomials over QQ (so performance over ZZ is irrelevant). For the examples I offered, the determinants were characteristic polynomials but this would not be true for the cases I want to study. Also I would be computing tens of thousands of these determinants, ideally with matrices of orders of up to 30 x 30. Eventually I may want to look at cases where the entries are polynomials in two or three variables. So this leads to the following questions. What algorithm(s) does sage use to compute determinants over QQ[t] or QQ[t,u]? Does they work over the ring of definition, or over the field of fractions? Are they polynomial time? My limited experiments seem to suggest that the default algorithm sage uses for matrices over QQ[t] is not polynomial time. As the Reference Manual suggests, I entered M.determinant? to see what algorithm was being used, but did not get any useful information. Thanks Chris On Mar 19, 4:17 am, Chris Godsil cgod...@uwaterloo.ca wrote: I want to compute determinants of matrix polynomials, for matrices up to 20 x 20, say. The attached transcript seems to indicate 9 or 10 might be my limit. (Or it's late and I am being stupd?) -- | Sage Version 3.4, Release Date: 2009-03-11 | | Type notebook() for the GUI, and license() for information. | -- # intel mac pro, binary distribution sage: P = graphs.PetersenGraph() sage: P.delete_edge([0,1]) sage: P.degree() [2, 2, 3, 3, 3, 3, 3, 3, 3, 3] sage: P Petersen graph: Graph on 10 vertices ## but P is not the Petersen graph now sage: A = P.am() sage: Id = identity_matrix(10) sage: R.t = QQ[] sage: (t+1)^5 t^5 + 5*t^4 + 10*t^3 + 10*t^2 + 5*t + 1 sage: M = t*Id - A; M [ t 0 0 0 -1 -1 0 0 0 0] [ 0 t -1 0 0 0 -1 0 0 0] [ 0 -1 t -1 0 0 0 -1 0 0] [ 0 0 -1 t -1 0 0 0 -1 0] [-1 0 0 -1 t 0 0 0 0 -1] [-1 0 0 0 0 t 0 -1 -1 0] [ 0 -1 0 0 0 0 t 0 -1 -1] [ 0 0 -1 0 0 -1 0 t 0 -1] [ 0 0 0 -1 0 -1 -1 0 t 0] [ 0 0 0 0 -1 0 -1 -1 0 t] sage: M.det() ## and sage hangs ## but the following worked sage: K =graphs.CompleteGraph(3) sage: B =K.am() sage: Id = identity_matrix(3) sage: (t*Id-B).det() t^3 - 3*t - 2 sage: C = graphs.CubeGraph(3) sage: C 3-Cube: Graph on 8 vertices sage: Id = identity_matrix(8) sage: (t*Id-C.am()).det() t^8 - 12*t^6 + 30*t^4 - 28*t^2 + 9 # and the cycle on 9 vertices hangs --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: determinants of matrix polynomials
Hi Chris, On Fri, Mar 20, 2009 at 1:54 AM, Chris Godsil cgod...@uwaterloo.ca wrote: SNIP As the Reference Manual suggests, I entered M.determinant? to see what algorithm was being used, but did not get any useful information. For the specified matrix M as defined above in your original email, I entered this sage: M.determinant? in Sage 3.4 and received the following snippet of info: ALGORITHM: For small matrices (n4), this is computed using the naive formula For integral domains, the charpoly is computed (using hessenberg form) Otherwise this is computed using the very stupid expansion by minors stupid *naive generic algorithm*. For matrices over more most rings more sophisticated algorithms can be used. (Type ``A.determinant?`` to see what is done for a specific matrix A.) But I don't think that snippet on algorithm helps in answering your question on the specific (implementation of) algorithms. -- Regards Minh Van Nguyen --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: showing graphs with multiple edges
davidp wrote:
Sorry. I was not being clear. I was surprised by the fact that
*only* the latter shows multiple edges.
I am also surprised that arrowheads don't appear with multiple edges.
This is especially a problem with weighted digraphs.
(By the way, it probably would have been better for me to have written
sage: G = DiGraph({1:{2: 2}, 2:{1:1}}, weighted=True)
so that the Laplacian comes out correctly. However, this doesn't help
with my problem.)
Well, the lack of arrowheads on weighted graphs is the problem in the
second case. Because the 0,1 entry is -1, Sage assumes that the matrix
represents a weighted graph.
Thanks,
Jason
Dave
On Mar 19, 6:01 pm, Jason Grout jason-s...@creativetrax.com wrote:
davidp wrote:
Hi,
I was a bit surprised by the difference exhibited below:
sage: G = DiGraph({1:{2: 2}, 2:{1:1}})
sage: G.show()
I'm surprised by the output of this. There are clearly two edges in the
graph: 1-2 and 2-1, but only one edge is shown.
sage: DiGraph(G.laplacian_matrix()).show()
The Laplacian matrix has nonzero entries indicating edges from each
vertex to each other vertex, so why do you find it surprising that there
are two edges?
sage: H=DiGraph(G.laplacian_matrix())
sage: H.edges()
[(0, 0, 1), (0, 1, -1), (1, 0, -1), (1, 1, 1)]
I find it surprising that arrowheads don't appear in the following, though:
sage: DiGraph(G.laplacian_matrix()).show()
Thanks,
Jason
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[sage-support] Re: determinants of matrix polynomials
Hi Chris, I'm not sure what other types of matrices you're looking at, but if the matrices are similar to the ones you posted, then one typical approach is to evaluate the matrices at a number of points, take the determinant, and then rebuild the determinant from that data. This work well if you have a good degree bound on the entries since it reduces the number of determinants you have to take. Here is a (very) rough function that does this: def poly_det(m, degree_bound): #Get a bunch of points to evaluate the determinant at points = range(degree_bound+1) n = len(points) #Evaluate the matrix at a number of points and compute #the determinant evaluations = [m.apply_map(lambda x: x(p)).det() for p in points] #Rebuild the polynomial determinant det_matrix = matrix( [[p^i for i in range(n)] for p in points] ) coefficients = det_matrix.solve_right(vector(evaluations)) #Return the polynomial R = PolynomialRing(QQ, 't') return R(list(coefficients)) Then, on my machine: sage: C = graphs.CycleGraph(9) sage: m = t - C.am() sage: %time m.det() t^9 - 9*t^7 + 27*t^5 - 30*t^3 + 9*t - 2 CPU time: 24.74 s, Wall time: 25.81 s sage: %time poly_det(m, len(C)) t^9 - 9*t^7 + 27*t^5 - 30*t^3 + 9*t - 2 CPU time: 0.06 s, Wall time: 0.06 s With this approach all of the hard linear algebra ends up being done with fast integer linear algebra: QQ[t] - QQ - ZZ. --Mike --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: determinants of matrix polynomials
On Mar 19, 6:54 pm, Chris Godsil cgod...@uwaterloo.ca wrote: What algorithm(s) does sage use to compute determinants over QQ[t] or QQ[t,u]? For both of these, it is computing them using minors, which is awful when the matrices are not tiny. Does they work over the ring of definition, or over the field of fractions? These work over the ring of definition. If you work over the field of fractions, then you can get some speedup since you can put then matrix in Hessenberg form and read the determinant off from the characteristic polynomial. For the CycleGraph(9): sage: m.change_ring(R.fraction_field()).det() t^9 - 9*t^7 + 27*t^5 - 30*t^3 + 9*t - 2 CPU time: 0.54 s, Wall time: 0.57 s over QQ[t] is not polynomial time. As the Reference Manual suggests, I entered M.determinant? to see what algorithm was being used, but did not get any useful information. In this case, doing M.determinant?? to see the actual source code gives you everything it's doing. --Mike --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Pynac bug
Here's another one for you, Burcin...
Alex
sage: var('n',ns=1)
n
sage: (QQbar(2)^3)^n
---
TypeError Traceback (most recent call
last)
/Users/arai021/ipython console in module()
/Applications/sage/local/lib/python2.5/site-packages/sage/rings/
qqbar.pyc in __pow__(self, e)
2808 1
2809
- 2810 e = QQ._coerce_(e)
2811 n = e.numerator()
2812 d = e.denominator()
/Applications/sage/local/lib/python2.5/site-packages/sage/structure/
parent_old.so in sage.structure.parent_old.Parent._coerce_ (sage/
structure/parent_old.c:4031)()
/Applications/sage/local/lib/python2.5/site-packages/sage/structure/
parent.so in sage.structure.parent.Parent.coerce (sage/structure/
parent.c:4185)()
TypeError: no canonical coercion from New Symbolic Ring to Rational
Field
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[sage-support] Re: sage problem
On Thu, Mar 19, 2009 at 6:14 PM, ARMAND BRUMER bru...@fordham.edu wrote:
Hi William,
This is my first attempt to use sage. I have OSX 10.4.11 and just downloaded
it.
I wanted to use liu's program. After trying out your examples and getting
the same result, I tried the example I was curious about and here is the
output. Can you do better. Did I screw up?
Thanks,
armand
sage: genus2reduction(x^3 + x^2 + x,-2*x^5 + 3*x^4 - x^3 - x^2 - 6*x - 2)
---
ValueError Traceback (most recent call last)
You have found a bug in Sage.When I try the above by directly
using Liu's program (note that i have to remove the spaces in the
polynomials and use an explanation point to run the program), I get
the following problem:
sage: !genus2reduction
enter Q(x) : x^3+x^2+x
enter P(x) : -2*x^5+3*x^4-x^3-x^2-6*x-2
factorization CPU time = 5
a minimal equation over Z[1/2] is :
y^2 = x^6+18*x^3+36*x^2-27
factorization of the minimal (away from 2) discriminant :
[2,1;3,15;53,1]
p=2
(potential) stable reduction : (II), j=1
reduction at p : [I{1-0-0}] page 170, (1), f=1
p=3
(potential) stable reduction : (I)
reduction at p : *** expected character: ',' instead of: mod(y,y^2-3)
I don't know if this ever worked, but I bet it did, and PARI changed
from 2004 or whatever, until now, and we just didn't pick up the
change because we didn't test genus2reduction enough.
2. A second problem is that if genus2reduction works once, then fails,
then it fails to work again:
sage: R = genus2reduction(x^3 - 2*x^2 - 2*x + 1, -5*x^5)
sage: R.conductor
1416875
sage: R = genus2reduction(x^3 + x^2 + x,-2*x^5 + 3*x^4 - x^3 - x^2 - 6*x - 2)
Traceback (most recent call last):
ValueError: error in input; possibly singular curve? (Q=x^3 + x^2 + x,
P=-2*x^5 + 3*x^4 - x^3 - x^2 - 6*x - 2)
sage: R = genus2reduction(x^3 - 2*x^2 - 2*x + 1, -5*x^5) # just worked above
Traceback (most recent call last):
...
ValueError: error in input; possibly singular curve? (Q=x^3 - 2*x^2 -
2*x + 1, P=-5*x^5)
---
When we fix this, we will of course have to write code to run through
random curves and verify that genus2reduction works sensibly on
millions of inputs.
Liu's program genus2reduction, included with Sage, is a C program that
is written to use the Pari C library.
I've posted the above to our bug tracking system:
http://trac.sagemath.org/sage_trac/ticket/5573
Please report any and all other issues you find with Sage. I'll email
you when the above gets fixed.
-- William
/Users/armandbrumer/sage/ipython console in module()
/Users/armandbrumer/sage/local/lib/python2.5/site-packages/sage/interfaces/genus2reduction.pyc
in __call__(self, Q, P)
356 from sage.misc.all import sage_eval
357
-- 358 s, Q, P = self.raw(Q, P)
359 raw = s
360
/Users/armandbrumer/sage/local/lib/python2.5/site-packages/sage/interfaces/genus2reduction.pyc
in raw(self, Q, P)
347 s = E.eval(str(P).replace(' ',''))
348 except RuntimeError:
-- 349 raise ValueError, error in input; possibly singular
curve? (Q=%s, P=%s)%(Q,P)
350 i = s.find('a minimal')
351 j = s.rfind(']')
ValueError: error in input; possibly singular curve? (Q=x^3 + x^2 + x,
P=-2*x^5 + 3*x^4 - x^3 - x^2 - 6*x - 2)
--
William Stein
Associate Professor of Mathematics
University of Washington
http://wstein.org
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[sage-support] Re: determinants of matrix polynomials
Chris, Some flakiness with Google Groups. Here's the rest of what I wanted to say. Sage is *very* fast over ZZ, and I know you said that was irrelevant. Use the command in the previous message to scale out the fractions, do your computation, and then move the scalar back in to the result. Not sure what you are up to exactly, but with determinants and polynomials, perhaps the scaling has a predictable effect. I like the looks of Mike's suggestion very much, and if this helps you get there, then I think thousands of 30x30's are achievable. Rob On Mar 19, 9:29 pm, Rob Beezer goo...@beezer.cotse.net wrote: Chris, I'm having trouble posting a reply here. Here's the essence of what I wanted to show you. Perhaps more in just a minute. sage: m=matrix(QQ, [[3/2, 4/3], [1/7, 5/11]) sage: m._clear_denoms() ([693 616] [ 66 210], 462) Rob On Mar 19, 8:13 pm, Mike Hansen mhan...@gmail.com wrote: On Mar 19, 6:54 pm, Chris Godsil cgod...@uwaterloo.ca wrote: What algorithm(s) does sage use to compute determinants over QQ[t] or QQ[t,u]? For both of these, it is computing them using minors, which is awful when the matrices are not tiny. Does they work over the ring of definition, or over the field of fractions? These work over the ring of definition. If you work over the field of fractions, then you can get some speedup since you can put then matrix in Hessenberg form and read the determinant off from the characteristic polynomial. For the CycleGraph(9): sage: m.change_ring(R.fraction_field()).det() t^9 - 9*t^7 + 27*t^5 - 30*t^3 + 9*t - 2 CPU time: 0.54 s, Wall time: 0.57 s over QQ[t] is not polynomial time. As the Reference Manual suggests, I entered M.determinant? to see what algorithm was being used, but did not get any useful information. In this case, doing M.determinant?? to see the actual source code gives you everything it's doing. --Mike --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: determinants of matrix polynomials
On Thu, Mar 19, 2009 at 9:33 PM, Rob Beezer goo...@beezer.cotse.net wrote: Chris, Some flakiness with Google Groups. Here's the rest of what I wanted to say. Sage is *very* fast over ZZ, and I know you said that was irrelevant. Use the command in the previous message to scale out the fractions, do your computation, and then move the scalar back in to the result. Not sure what you are up to exactly, but with determinants and polynomials, perhaps the scaling has a predictable effect. I like the looks of Mike's suggestion very much, and if this helps you get there, then I think thousands of 30x30's are achievable. Mike's multimodular method is probably a pretty good first nontrivial approach to this problem. Chris -- you might want to talk with Arne Storjohann since he's probably the world expert on algorithms for computing determinants of matrices with entries in QQ[t], and he's in the same department as you. He's also responsible for IML, which is the library at the heart of Sage's current code for computing det's over QQ and ZZ. Asymptotically -- for matrices with large entries -- Sage is by far the world's fastest program for computing determinants (e.g, handily beating Magma). Rob -- Sage computes det's over QQ currently internally by rescaling to ZZ and computing the det there. -- 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: sage problem
On Thu, Mar 19, 2009 at 9:56 PM, ARMAND BRUMER bru...@fordham.edu wrote: Thanks, Bill, for your prompt reply. I had noticed the second phenomenon and attributed it to my not knowing how to use sage properly! By the way, if you can get the conductor exponent at 3, I would be grateful. Liu's paper goes becomes a bit unclear with precisely this type of example. I think it is 3^2, but would like an independent check! Thanks again, armand PS I was trying to circumvent having to learn C to attach Liu's program to Pari (that I also do not have!) I had an old version in Maple of Liu's program, but wanted to confirm... Does the Maple program work on your input example? 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
