[sage-support] Re: sage -wiki not starting
^^^ This is some sort of permission error. Are you running SELinux or something like that? Just to confirm. SELinux was added to the computer. I am now 'negotiating' with IT. :-) cheers, Adam --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] working with rings
If I do: sage: MS = MatrixSpace(IntegerModRing(9), 5,5) sage: G = MS([[5, 0, 0, 0, 4],[4, 5, 0, 0, 0],[0, 4, 5, 0, 0],[0, 0,4, 5, 0], [0, 0, 0, 4, 5]]) sage: G.base_ring() Ring of integers modulo 9 is there a way to get the base ring as an integer?, i.e. I want to know the base ring to work with it in a cython program,let's say I want to do arithmetic with the base ring integer. --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] a problem starting the notebook
I start sage and I type notebook and firefox is open to the following address: http://localhost:8000/?startup_token=1af26f2b14cac678ab97c121c9cca7c5 which is not found, so I have to cut it just to http://localhost:8000, is there a way to solve this problem? --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: working with rings
Hello, On Mon, Sep 22, 2008 at 11:34 PM, cesarnda [EMAIL PROTECTED] wrote: If I do: sage: MS = MatrixSpace(IntegerModRing(9), 5,5) sage: G = MS([[5, 0, 0, 0, 4],[4, 5, 0, 0, 0],[0, 4, 5, 0, 0],[0, 0,4, 5, 0], [0, 0, 0, 4, 5]]) sage: G.base_ring() Ring of integers modulo 9 is there a way to get the base ring as an integer? Do you mean you want the matrix as a matrix over the integers rather than over the integers mod 9? If so, then you can do the following: sage: H = G.change_ring(ZZ); H [5 0 0 0 4] [4 5 0 0 0] [0 4 5 0 0] [0 0 4 5 0] [0 0 0 4 5] sage: H.base_ring() Integer Ring --Mike --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Mercurial problems in 3.1.2
On Sep 22, 2008, at 22:24 , mabshoff wrote: Nope, none of those fixes is in alpha0, but I hope that at least some of them will make it into alpha1, due out late tomorrow. I still don't see how parallel make impacts numpy, so if you could send me the portion of the blown up numpy build with parallel make I could attempt to figure out what is wrong. See sage.math.washington.edu:~justin/logs/sage-numpy.log (the whole shebang; maybe something early on triggered it :-}). Justin -- Justin C. Walker, Curmudgeon-At-Large Institute for the Enhancement of the Director's Income When LuteFisk is outlawed, Only outlaws will have LuteFisk --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: sage -wiki not starting
On Sep 22, 11:32 pm, Adam Webb [EMAIL PROTECTED] wrote: ^^^ This is some sort of permission error. Are you running SELinux or something like that? Hi Adam, Just to confirm. SELinux was added to the computer. I am now 'negotiating' with IT. :-) good luck negotiating :). You can relabel all the files so that Sage and SELinux can play well together, but adding new pages to the wiki might prove difficult since those new files need to inherit the right ACLs. cheers, Adam Cheers, Michael --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: working with rings
On Sep 22, 2008, at 11:37 PM, Mike Hansen wrote: Hello, On Mon, Sep 22, 2008 at 11:34 PM, cesarnda [EMAIL PROTECTED] wrote: If I do: sage: MS = MatrixSpace(IntegerModRing(9), 5,5) sage: G = MS([[5, 0, 0, 0, 4],[4, 5, 0, 0, 0],[0, 4, 5, 0, 0],[0, 0,4, 5, 0], [0, 0, 0, 4, 5]]) sage: G.base_ring() Ring of integers modulo 9 is there a way to get the base ring as an integer? Do you mean you want the matrix as a matrix over the integers rather than over the integers mod 9? If so, then you can do the following: sage: H = G.change_ring(ZZ); H [5 0 0 0 4] [4 5 0 0 0] [0 4 5 0 0] [0 0 4 5 0] [0 0 0 4 5] sage: H.base_ring() Integer Ring Or, if you meant the modulus of the ring, you can get that with sage: G.base_ring().order() 9 - Robert --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Mercurial problems in 3.1.2
On Sep 22, 11:39 pm, Justin C. Walker [EMAIL PROTECTED] wrote: On Sep 22, 2008, at 22:24 , mabshoff wrote: Nope, none of those fixes is in alpha0, but I hope that at least some of them will make it into alpha1, due out late tomorrow. I still don't see how parallel make impacts numpy, so if you could send me the portion of the blown up numpy build with parallel make I could attempt to figure out what is wrong. See sage.math.washington.edu:~justin/logs/sage-numpy.log (the whole shebang; maybe something early on triggered it :-}). Thanks. Numpy is complaining about a missing math module, but I think that is more likely caused by the libpng.dylib disaster than anything else. I just checked the python.spkg and we are running make install with parallel make, which I would guess is not a good idea :) The ticket for that issue is #4174 and there should be an spkg shortly. Justin Cheers, Michael -- Justin C. Walker, Curmudgeon-At-Large Institute for the Enhancement of the Director's Income When LuteFisk is outlawed, Only outlaws will have LuteFisk --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Suggestions for the notebook
Okay that's right. But still, #auto doesn't work together with %hide or %latex, no matter which order I put these commands in, and I need this feature for my %latex cells, because they're the ones not being executed when I start up a worksheet. Maike On Sep 22, 6:31 pm, William Stein [EMAIL PROTECTED] wrote: On 9/22/08, Maike [EMAIL PROTECTED] wrote: Hmmm, I get NameError: name 'auto' is not defined. I'm using version 3.1.1, should that support %auto? Use #auto, not %auto Thanks! Maike On Sep 22, 12:06 pm, Mike Hansen [EMAIL PROTECTED] wrote: Hi Maike, On Mon, Sep 22, 2008 at 3:04 AM, Maike [EMAIL PROTECTED] wrote: (2) Thanks that sounds good. I'm not sure how to use #auto though, where do I put this option? You put %auto as the first line of the cell that you want to auto-evaluate. --Mike -- William Stein Associate Professor of Mathematics University of Washingtonhttp://wstein.org --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Suggestions for the notebook
Hello, On Tue, Sep 23, 2008 at 1:21 AM, Maike [EMAIL PROTECTED] wrote: Okay that's right. But still, #auto doesn't work together with %hide or %latex, no matter which order I put these commands in, and I need this feature for my %latex cells, because they're the ones not being executed when I start up a worksheet. There was a bug in Sage 3.1.1 that caused any associated files or images with a cell (such as plots or the output of %latex cells) to be deleted when the worksheet was closed. If this is the reason why you want to use the auto cells, you should upgrade to Sage 3.1.2 since I fixed this bug in it. This should alleviate some of your problems. --Mike --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Suggestions for the notebook
Thanks, I'll make sure I get 3.1.2 installed today! On Sep 23, 10:26 am, Mike Hansen [EMAIL PROTECTED] wrote: Hello, On Tue, Sep 23, 2008 at 1:21 AM, Maike [EMAIL PROTECTED] wrote: Okay that's right. But still, #auto doesn't work together with %hide or %latex, no matter which order I put these commands in, and I need this feature for my %latex cells, because they're the ones not being executed when I start up a worksheet. There was a bug in Sage 3.1.1 that caused any associated files or images with a cell (such as plots or the output of %latex cells) to be deleted when the worksheet was closed. If this is the reason why you want to use the auto cells, you should upgrade to Sage 3.1.2 since I fixed this bug in it. This should alleviate some of your problems. --Mike --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: working with rings
Actually sage: G.base_ring().order() is what I wanted, thank you so much. On Sep 23, 1:42 am, Robert Bradshaw [EMAIL PROTECTED] wrote: On Sep 22, 2008, at 11:37 PM, Mike Hansen wrote: Hello, On Mon, Sep 22, 2008 at 11:34 PM, cesarnda [EMAIL PROTECTED] wrote: If I do: sage: MS = MatrixSpace(IntegerModRing(9), 5,5) sage: G = MS([[5, 0, 0, 0, 4],[4, 5, 0, 0, 0],[0, 4, 5, 0, 0],[0, 0,4, 5, 0], [0, 0, 0, 4, 5]]) sage: G.base_ring() Ring of integers modulo 9 is there a way to get the base ring as an integer? Do you mean you want the matrix as a matrix over the integers rather than over the integers mod 9? If so, then you can do the following: sage: H = G.change_ring(ZZ); H [5 0 0 0 4] [4 5 0 0 0] [0 4 5 0 0] [0 0 4 5 0] [0 0 0 4 5] sage: H.base_ring() Integer Ring Or, if you meant the modulus of the ring, you can get that with sage: G.base_ring().order() 9 - Robert --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: question on using integral() in sage. Fourier transform of unit step function.
Surprinsingly, SAGE 3.1.2 is more ignorant than 3.1.1:
./sage
---
| SAGE Version 3.1.2 ...
| Type notebook() ...
--
sage: var('a b t x')
(a, b, t, x)
sage: assume(exp(b*pi)1)
sage: expr(x)=integral(exp(-2*I*pi*(a+I*b)*t),t,0,x)
sage: factor(limit(expr(x),x=infinity))
-1*I/(2*pi*(I*b+a))
SAGE doesn't know anymore that exp() is strictly ascending.
(assume(b0) doesn't work anymore)
On 22 sep, 12:30, kkwweett [EMAIL PROTECTED] wrote:
you can indirectly get
./sage
---
| SAGE Version 3.1.1 ...
| Type notebook() ...
--
sage: var('a b t x')
(a, b, t, x)
sage: assume(b0)
sage: expr(x)=integral(exp(-2*I*pi*(a+I*b)*t),t,0,x)
sage: factor(limit(expr(x),x=infinity))
-1*I/(2*pi*(I*b+a))
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[sage-support] operations with matrices
hi, I wanted to know if there is a way to work in Sage with arrays of matrices or something similar (something like a[i,j,k], so that a[i,:,:], a[:,j,:] and a[:,:,k] are all matrices. I tried to use a list of matrices but apparently sage interprets it as a list of vectors: sage: m=matrix(RR,2,range(1,5)) sage: m1=matrix(RR,2,range(6,10)) sage: lm=list(m) sage: lm.append(m1) sage: lm [(1.00, 2.00), (3.00, 4.00), [6.00 7.00] [8.00 9.00]] sage: lm[1] (3.00, 4.00) I also wanted to know if there is a command to create a list (or matrix, or vector) of equal elements; to sum the entries of vectors, particularly of rows of matrices, thanks in advance, Aniura --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: operations with matrices
On Sep 23, 2008, at 8:45 AM, aniura wrote: hi, I wanted to know if there is a way to work in Sage with arrays of matrices or something similar (something like a[i,j,k], so that a[i,:,:], a[:,j,:] and a[:,:,k] are all matrices. I tried to use a list of matrices but apparently sage interprets it as a list of vectors: sage: m=matrix(RR,2,range(1,5)) sage: m1=matrix(RR,2,range(6,10)) sage: lm=list(m) sage: lm.append(m1) sage: lm You should do lm = [m] lm.append(m1) instead. When you call list(m) you are asking to *convert* the matrix to a list. david --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: operations with matrices
If you type m.tab you will see lots of things you can do with a matrix m. For example m.subdivide? allows you to pick out a submatrix. The rest of your query is hard to interpret. To create a list of equal elements, say a list of 5 copies of the matrix m, do this: sage: [m]*5 [[1.00 2.00] [3.00 4.00], [1.00 2.00] [3.00 4.00], [1.00 2.00] [3.00 4.00], [1.00 2.00] [3.00 4.00], [1.00 2.00] [3.00 4.00]] To add the entries of a vector: sage: v=vector(range(100)) sage: sum(v) 4950 I'll leave row sums of a matrix as an exercise! John Cremona 2008/9/23 aniura [EMAIL PROTECTED]: hi, I wanted to know if there is a way to work in Sage with arrays of matrices or something similar (something like a[i,j,k], so that a[i,:,:], a[:,j,:] and a[:,:,k] are all matrices. I tried to use a list of matrices but apparently sage interprets it as a list of vectors: sage: m=matrix(RR,2,range(1,5)) sage: m1=matrix(RR,2,range(6,10)) sage: lm=list(m) sage: lm.append(m1) sage: lm [(1.00, 2.00), (3.00, 4.00), [6.00 7.00] [8.00 9.00]] sage: lm[1] (3.00, 4.00) I also wanted to know if there is a command to create a list (or matrix, or vector) of equal elements; to sum the entries of vectors, particularly of rows of matrices, thanks in advance, Aniura --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: operations with matrices
John Cremona 2008/9/23 aniura [EMAIL PROTECTED]: hi, I wanted to know if there is a way to work in Sage with arrays of matrices or something similar (something like a[i,j,k], so that a[i,:,:], a[:,j,:] and a[:,:,k] are all matrices. I tried to use a list of matrices but apparently sage interprets it as a list of vectors: sage: m=matrix(RR,2,range(1,5)) sage: m1=matrix(RR,2,range(6,10)) sage: lm=list(m) sage: lm.append(m1) sage: lm [(1.00, 2.00), (3.00, 4.00), [6.00 7.00] [8.00 9.00]] sage: lm[1] (3.00, 4.00) I also wanted to know if there is a command to create a list (or matrix, or vector) of equal elements; to sum the entries of vectors, particularly of rows of matrices, thanks in advance, Aniura Depending on what you're doing, you may also want to look into numpy arrays, which you can use from within Sage. from numpy import array You might also want to work in python mode (%python as the first line of a cell in the notebook) if you're doing much in numpy, to avoid having ints get preprocessed to Integers, etc. Regards, JM --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] installation problem with sage-3.1.2
I am trying to install sage-3.1.2 on my Fedora 9 with gcc-4.3. I am having problem with matplotlib-0.98.3.p1its giving error given below BUILDING MATPLOTLIB matplotlib: 0.98.3 python: 2.5.2 (r252:60911, Sep 23 2008, 17:09:57) [GCC 4.3.0 20080428 (Red Hat 4.3.0-8)] platform: linux2 REQUIRED DEPENDENCIES numpy: 1.1.0 freetype2: 9.16.3 OPTIONAL BACKEND DEPENDENCIES libpng: 1.2.29 Traceback (most recent call last): File setup.py, line 125, in module if check_for_tk() or (options['build_tkagg'] is True): File /home/abhishek/sage-3.1.2/spkg/build/matplotlib-0.98.3.p1/src/ setupext.py, line 846, in check_for_tk explanation = add_tk_flags(module) File /home/abhishek/sage-3.1.2/spkg/build/matplotlib-0.98.3.p1/src/ setupext.py, line 1106, in add_tk_flags module.libraries.extend(['tk' + tk_ver, 'tcl' + tk_ver]) UnboundLocalError: local variable 'tk_ver' referenced before assignment Error building matplotlib package. plz help --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: operations with matrices
On Sep 23, 3:31 pm, John Cremona [EMAIL PROTECTED] wrote: The rest of your query is hard to interpret. To create a list of equal elements, say a list of 5 copies of the matrix m, do this: sage: [m]*5 But this would not create a list of 5 *copies* of m. The five entries of that list are one and the same object, namely m: sage: m=Matrix(ZZ,[[1,2,3]]) sage: L=[m]*5 sage: L[0] is L[1] True Any change to L[0] would also imply a change to L[1] and even to m: sage: L[1] [1 2 3] sage: L[0][0,0]=0 sage: L[1] [0 2 3] sage: m [0 2 3] Hence, Aniura, if you want to manipulate individual copies of m, then you should do sage: L=[copy(m) for i in range(5)] Then, you have sage: L[0] is L[1] False sage: L=[copy(m) for i in range(5)] sage: L[1] [1 2 3] sage: L[0][0,0]=0 sage: L[0] [0 2 3] sage: L[1] [1 2 3] sage: m [1 2 3] But i am afraid that does not answer the question of the original post, which was about creating an array A such that A[i;;], A[;j;] and A[;;k] are matrices. Jason's reply (use numpy) is probably better. Cheers Simon --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: operations with matrices
2008/9/23 Simon King [EMAIL PROTECTED]: On Sep 23, 3:31 pm, John Cremona [EMAIL PROTECTED] wrote: The rest of your query is hard to interpret. To create a list of equal elements, say a list of 5 copies of the matrix m, do this: sage: [m]*5 But this would not create a list of 5 *copies* of m. The five entries of that list are one and the same object, namely m: Excellent point, thanks for correcting me! --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] question about SAGE eigenvalues
I tried sage: A=matrix([[1,1],[2,3]]) sage: A.eigenvalues() [0.2679491924311228?, 3.732050807568878?] My question is why the last digit before ? in 0.2679491924311228? is '8'? Shouldn't it be 7 according to sage: ch=characteristic_polynomial(A) sage: solve(ch(x)==0,x) [x == 2 - sqrt(3), x == sqrt(3) + 2] sage: N(2-sqrt(3), digits=18) 0.267949192431122706 --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: question about SAGE eigenvalues
On Tue, Sep 23, 2008 at 9:34 AM, pong [EMAIL PROTECTED] wrote: I tried sage: A=matrix([[1,1],[2,3]]) sage: A.eigenvalues() [0.2679491924311228?, 3.732050807568878?] My question is why the last digit before ? in 0.2679491924311228? is '8'? Shouldn't it be 7 according to ? means the digit before the ? is unknown. This is an algebraic number printed as an element of QQbar. You can always get it to higher precision. sage: RealField(100)(A.eigenvalues()[0]) 0.26794919243112270647255365849 William sage: ch=characteristic_polynomial(A) sage: solve(ch(x)==0,x) [x == 2 - sqrt(3), x == sqrt(3) + 2] sage: N(2-sqrt(3), digits=18) 0.267949192431122706 -- 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: question about SAGE eigenvalues
2008/9/23 pong [EMAIL PROTECTED]: I tried sage: A=matrix([[1,1],[2,3]]) sage: A.eigenvalues() [0.2679491924311228?, 3.732050807568878?] My question is why the last digit before ? in 0.2679491924311228? is '8'? Shouldn't it be 7 according to sage: ch=characteristic_polynomial(A) sage: solve(ch(x)==0,x) [x == 2 - sqrt(3), x == sqrt(3) + 2] sage: N(2-sqrt(3), digits=18) 0.267949192431122706 Alternatively: sage: e1,e2= A.eigenvalues() sage: e1 0.2679491924311228? sage: e1.interval(ComplexIntervalField(53)) # the default is 53 bits precision 0.2679491924311228? sage: e1.interval(ComplexIntervalField(100)) 0.267949192431122706472553658494? sage: e1.interval(ComplexIntervalField(200)) 0.267949192431122706472553658494127633057194746189619371944193? i.e. e1 is a number of a type which is essentially infinite precision, and you can ask for it to any desired precision later. However I'm still not sure why the original display ends 8? and not 7?. The ? notatation was introduced quite recently, so I am not sure whether this is a feature or a bug. John Cremona --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: sage -wiki not starting
Hi, ^^^ This is some sort of permission error. Are you running SELinux or something like that? It turns out that although SELinux is installed it is actually disabled because it interferes to much and since I live behind a firewall it deemed unneeded. So I am back to square one. At the moment I went into the last file in the traceback: sage/local/ lib/python2.5/site-packages/twisted/python/util.py and put in a statement to set setgroups and getgroups to None. If I understand the comments, this forces the case where the OS does not support this. My initial test is that this works but I have no idea what the side effects might be. Adam --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: question about SAGE eigenvalues
2008/9/23 John Cremona [EMAIL PROTECTED]: 2008/9/23 pong [EMAIL PROTECTED]: I tried sage: A=matrix([[1,1],[2,3]]) sage: A.eigenvalues() [0.2679491924311228?, 3.732050807568878?] My question is why the last digit before ? in 0.2679491924311228? is '8'? Shouldn't it be 7 according to sage: ch=characteristic_polynomial(A) sage: solve(ch(x)==0,x) [x == 2 - sqrt(3), x == sqrt(3) + 2] sage: N(2-sqrt(3), digits=18) 0.267949192431122706 Alternatively: sage: e1,e2= A.eigenvalues() sage: e1 0.2679491924311228? sage: e1.interval(ComplexIntervalField(53)) # the default is 53 bits precision 0.2679491924311228? sage: e1.interval(ComplexIntervalField(100)) 0.267949192431122706472553658494? sage: e1.interval(ComplexIntervalField(200)) 0.267949192431122706472553658494127633057194746189619371944193? i.e. e1 is a number of a type which is essentially infinite precision, and you can ask for it to any desired precision later. However I'm still not sure why the original display ends 8? and not 7?. The ? notatation was introduced quite recently, so I am not sure whether this is a feature or a bug. OK, it is a feature. To quote from http://wiki.sagemath.org/sage-3.1.2 (Release notes for 3.1.2): The question marks at the end of the numbers in the previous example mean that Sage is printing out an approximation of an exact value that it uses. In particular, the question mark means that the last digit can vary by plus or minus 1. In other words, 32.46424919657298? means that the exact number is really between 32.46424919657297 and 32.46424919657299. Sage knows what the exact number is and uses the exact number in calculations. So in Pong's case the final 8? means 8-plus-or-minus-1 which is not wrong. John Cremona --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Storing results of solve() function
Hi Andy, On Tue, Sep 23, 2008 at 12:58 PM, Andy [EMAIL PROTECTED] wrote: I am programming for a project in sage and I want to make use of the solve() function. However, I noticed that solve() does not return the value of the solved variable but only a statement instead. For instance, if I wanted to do solve([x^2 - 1], x), I would likely get a result containing the strings x == 1 and x == -1. This is all fine if I just want to view the result, but what if I wanted to store the resulting possible values of x in a list? Like have the list returned [-1, 1]. Any tricks to solve() that allow the results to be stored in a useable form? The results of solve() are Sage's symbolic equations. You can get at their left and right hand sides with lhs and rhs respectively. sage: eqs = solve([x^2 - 1], x); eqs [x == -1, x == 1] sage: [eq.rhs() for eq in eqs] [-1, 1] --Mike --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: question about SAGE eigenvalues
John Cremona wrote: 2008/9/23 John Cremona [EMAIL PROTECTED]: 2008/9/23 pong [EMAIL PROTECTED]: I tried sage: A=matrix([[1,1],[2,3]]) sage: A.eigenvalues() [0.2679491924311228?, 3.732050807568878?] My question is why the last digit before ? in 0.2679491924311228? is '8'? Shouldn't it be 7 according to sage: ch=characteristic_polynomial(A) sage: solve(ch(x)==0,x) [x == 2 - sqrt(3), x == sqrt(3) + 2] sage: N(2-sqrt(3), digits=18) 0.267949192431122706 Alternatively: sage: e1,e2= A.eigenvalues() sage: e1 0.2679491924311228? sage: e1.interval(ComplexIntervalField(53)) # the default is 53 bits precision 0.2679491924311228? sage: e1.interval(ComplexIntervalField(100)) 0.267949192431122706472553658494? sage: e1.interval(ComplexIntervalField(200)) 0.267949192431122706472553658494127633057194746189619371944193? i.e. e1 is a number of a type which is essentially infinite precision, and you can ask for it to any desired precision later. However I'm still not sure why the original display ends 8? and not 7?. The ? notatation was introduced quite recently, so I am not sure whether this is a feature or a bug. OK, it is a feature. To quote from http://wiki.sagemath.org/sage-3.1.2 (Release notes for 3.1.2): The question marks at the end of the numbers in the previous example mean that Sage is printing out an approximation of an exact value that it uses. In particular, the question mark means that the last digit can vary by plus or minus 1. In other words, 32.46424919657298? means that the exact number is really between 32.46424919657297 and 32.46424919657299. Sage knows what the exact number is and uses the exact number in calculations. That last sentence is technically incorrect, I think (sorry; I wrote it). It might be better to say, Sage carries out the calculations using interval arithmetic and essentially uses infinite precision in these cases. Carl, is there some way to word things better? Thanks, Jason --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] bug? with plot3d
When passing a python function to plot3d, specifying the variable names and including 'adaptive=True' makes plot3d fail, with the message AttributeError: 'function' object has no attribute 'subs' In more detail: sage: def f(x,y): return sin(x+y) Then the following work and produce the same graph: plot3d(f, (x, -5, 5), (y, -5, 5)) plot3d(f, (-5, 5), (-5, 5)) On the other hand, plot3d(f, (-5, 5), (-5, 5), adaptive=True) works, but plot3d(f, (x, -5, 5), (y, -5, 5), adaptive=True) barfs with the error message given above. Is this a bug, or is this related to one of the issues raised in this earlier thread http://groups.google.com/group/sage-support/browse_frm/thread/ 9ad07eeddb850ab3/e0cab1daca9b0883?lnk=gstq=plot3d#e0cab1daca9b0883 ? If it's not a bug, it should perhaps fail more gracefully, since the plot works if 'adaptive=False'. --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] a different bug? with plot3d
Is the following a bug? I don't really know what 'adaptive=True' means -- the documentation isn't very helpful -- so maybe it's not supposed to work for functions like this... def g(x,y): if y = 0 or y = x**2: return 0 else: return 1 Then plot3d(g, (-3, 3), (-3, 3), adaptive=True) fails, with the message Traceback (most recent call last): File stdin, line 1, in module File /home/palmieri/.sage/sage_notebook/worksheets/admin/37/code/ 7.py, line 6, in module plot3d(g, (-Integer(3), Integer(3)), (-Integer(3), Integer(3)), adaptive=True) File /usr/local/share/sage/local/lib/python2.5/site-packages/ SQLAlchemy-0.4.6-py2.5.egg/, line 1, in module File /home/palmieri/Documents/sage-3.1.2/local/lib/python2.5/site- packages/sage/plot/plot3d/plot3d.py, line 157, in plot3d P = plot3d_adaptive(f, urange, vrange, **kwds) File /home/palmieri/Documents/sage-3.1.2/local/lib/python2.5/site- packages/sage/plot/plot3d/plot3d.py, line 255, in plot3d_adaptive G.set_texture(texture[k], opacity=opacity) IndexError: list index out of range --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] atan(0,0) returning zero?
Hi, In some investigations while using Sage, I noticed that atan(0,0) returns 0 while using Sage. Maxima correctly reports an error. The arctan(0,0) should be undefined. Is there a specific reason for the behaviour of reporting 0? Is there a flag to set to make it raise an error? Thanks, Tim. --- Tim Lahey PhD Candidate, Systems Design Engineering University of Waterloo smime.p7s Description: S/MIME cryptographic signature
[sage-support] question about DiGraph
I tried one of the examples (example 3 in DiGraph?)
g = DiGraph({0:{1:'x',2:'z',3:'a'}, 2:{5:'out'}},
implementation='networkx'); show(g)
However, I don't see any label of the edges, why?
Also, I think the DiGraph function is very useful for drawing finite
automata (thanks!) My question is: does it support loop to a node?
(which is essential in drawing automata)
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