[sage-support] Extended complex numbers

2010-05-03 Thread jvkersch
Hi all, Is there a way to do extended complex arithmetic in Sage? I mean, adding a constant infinity such that oo + a = oo, a*oo = oo for a != 0, etc. For now, I just made a small class wrapping a standard complex number, but I wouldn't be surprised if this was already in Sage, and done in a mu

[sage-support] Re: New sage version?

2010-05-03 Thread Harald Schilly
On May 2, 9:52 pm, VictorMiller wrote: > I just downloaded, what I thought, was SAGE 4.4 (I went to > sagemath.org, download, and clicked on the server from Boston) for Mac > OS X 64 bit intel.   I upload the binaries and regarding osx, i only replace them if there is a newer version available. T

[sage-support] Elliptic curves over non-fields

2010-05-03 Thread Jeroen Demeyer
Hello sage-support, I wonder if there is a way to make Sage compute with points on elliptic curves over rings which are not fields. I would like to use it for a very simple implementation of the ECM factoring algorithm for educational purposes. The obvious doesn't work:

[sage-support] systems of inequalities over the integers

2010-05-03 Thread Diego Ruano
Hi, I would like to compute the solution of systems of inequalities over the integers. I have used the command "solve", but the solution is over the complex numbers. Something like: i, j = var('i,j') sol=solve([2*i+9*j>= - 0, -5*i-7*j>=-5, 3*i-2*j>= -6], i,j) sol [[i == (-54/31), j == (12/31)],

[sage-support] Re: New sage version?

2010-05-03 Thread Harald Schilly
On May 3, 9:54 am, Harald Schilly wrote: > far as i know ... ok well, i just forgot to upload it ^^ but anyways, the filename was 4.3.5 and hence a 4.3.5 release of sage. h -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage

[sage-support] how does sage compare symbolic expressions?

2010-05-03 Thread Maite Aranes
Does sage use symbolic calculus if it has to compare two symbolic expressions inside an "if" clause? I was expecting that this will be the case and I would get an "exact" answer to my "symbolic question", but a program I was running crashed when it failed in checking that two symbolic expressions w

[sage-support] Re: how does sage compare symbolic expressions?

2010-05-03 Thread Simon King
Hi Maite, On May 3, 11:15 am, Maite Aranes wrote: > Does sage use symbolic calculus if it has to compare two symbolic > expressions inside an "if" clause? I don't know much about the symbolic part of Sage, but I think that punch line is that the evaluation of a symbolic expression to a boolean r

[sage-support] Re: how does sage compare symbolic expressions?

2010-05-03 Thread Jason Grout
On 05/03/2010 06:45 AM, Simon King wrote: Hi Maite, On May 3, 11:15 am, Maite Aranes wrote: Does sage use symbolic calculus if it has to compare two symbolic expressions inside an "if" clause? I don't know much about the symbolic part of Sage, but I think that punch line is that the evaluati

[sage-support] Sage 4.4.1 upgrade error

2010-05-03 Thread Stephen Loo
Hi, I upgrade Sage from 4.4.1.rc0 to 4.4.1 release on Mac 10.6.4 x86-64 platform. Upgrade successful. When I run, it show following errors -- | Sage Version 4.4.1, Release Date: 2010-05-02 | | Type notebook(

[sage-support] Re: how does sage compare symbolic expressions?

2010-05-03 Thread Maite Aranes
Thanks for the very quick answers :) > > I don't know much about the symbolic part of Sage, but I think that > > punch line is that the evaluation of a symbolic expression to a > > boolean returns False if it is not guaranteed to be True. In your > > case, I could imagine that the symbolic sqrt(..

[sage-support] problem with viroable 2D arrays

2010-05-03 Thread hamed akhavan
Hello I want to introduce a series of variables which are 2-dimensional array (like M[i,j] in Mathematica software). In order to complete my question, I gave an example, below: I want to have a variable 2-D array like M that: M[1,1]=1, M[1,2]=3, M[2,1]=4, and then I want to solve an equation inc

Re: [sage-support] systems of inequalities over the integers

2010-05-03 Thread David Joyner
I think Sage calls Maxima and Maxima is getting i (your variable) and I (sqrt(-1)) mixed up. I guess this is a bug, but it might be known already. Anyway, using x's and y's might be safer: sage: x,y = var('x,y') sage: ineqs = [2*x+9*y>= - 0, -5*x-7*y>=-5, 3*x-2*y>= -6] sage: solve_ineq(ineqs,[x,y

Re: [sage-support] Elliptic curves over non-fields

2010-05-03 Thread Mike Hansen
Hello, On Mon, May 3, 2010 at 1:34 AM, Jeroen Demeyer wrote: > I wonder if there is a way to make Sage compute with points on elliptic > curves over rings which are not fields.  I would like to use it for a > very simple implementation of the ECM factoring algorithm for > educational purposes.  T

Re: [sage-support] systems of inequalities over the integers

2010-05-03 Thread Burcin Erocal
On Mon, 3 May 2010 10:18:42 -0400 David Joyner wrote: > I think Sage calls Maxima and Maxima is getting i (your variable) > and I (sqrt(-1)) mixed up. I guess this is a bug, but it might be > known already. It's reported here: http://trac.sagemath.org/sage_trac/ticket/6882 I'm hoping it will b

Re: [sage-support] Re: how does sage compare symbolic expressions?

2010-05-03 Thread Burcin Erocal
Hi, On Mon, 03 May 2010 06:55:25 -0500 Jason Grout wrote: > On 05/03/2010 06:45 AM, Simon King wrote: > > Hi Maite, > > > > On May 3, 11:15 am, Maite Aranes wrote: > >> Does sage use symbolic calculus if it has to compare two symbolic > >> expressions inside an "if" clause? > > > > I don't know

[sage-support] Problem with DiGraph.shortest_path_length in Sage 4.4

2010-05-03 Thread Diego Ruano
Hi, I have some computations that I used to run without problems in Sage 4.2 but they do not work anymore in Sage 4.4. I believe that I have problems when I use something different from 0,1,2, for the name of the vertices of a DiGraph. I get the same error in my laptop using the version for U

Re: [sage-support] systems of inequalities over the integers

2010-05-03 Thread Diego Ruano
Thank you David for your answer. What about getting a solution over the integers? David Joyner wrote: > I think Sage calls Maxima and Maxima is getting i (your variable) > and I (sqrt(-1)) mixed up. I guess this is a bug, but it might be > known already. > > Anyway, using x's and y's might be saf

Re: [sage-support] systems of inequalities over the integers

2010-05-03 Thread David Joyner
On Mon, May 3, 2010 at 12:50 PM, Diego Ruano wrote: > Thank you David for your answer. > > What about getting a solution over the integers? I'm sure of the best way. You could just write your own little function that checks the conditions for each (i,j) in a big rectangle. Also, you might be abl

[sage-support] Re: Problem with DiGraph.shortest_path_length in Sage 4.4

2010-05-03 Thread Jason Grout
On 05/03/2010 11:48 AM, Diego Ruano wrote: Hi, I have some computations that I used to run without problems in Sage 4.2 but they do not work anymore in Sage 4.4. I believe that I have problems when I use something different from 0,1,2, for the name of the vertices of a DiGraph. I get the sa

[sage-support] Re: systems of inequalities over the integers

2010-05-03 Thread Jason Grout
On 05/03/2010 09:51 AM, Burcin Erocal wrote: On Mon, 3 May 2010 10:18:42 -0400 David Joyner wrote: I think Sage calls Maxima and Maxima is getting i (your variable) and I (sqrt(-1)) mixed up. I guess this is a bug, but it might be known already. It's reported here: http://trac.sagemath.org/

[sage-support] Re: Elliptic curves over non-fields

2010-05-03 Thread John Cremona
There was another similar thread a few days ago, with a little more information. It would actually not be difficult to get this working naturally (famous last words). There is quite an old ticket already out for this (#1975, see http://trac.sagemath.org/sage_trac/ticket/1975). John On May 3, 9

[sage-support] Re: Problem with DiGraph.shortest_path_length in Sage 4.4

2010-05-03 Thread Robert Miller
Diego, On May 3, 9:48 am, Diego Ruano wrote: > Hi, > > I have some computations that I used to run without problems in Sage > 4.2 but they do not work anymore in Sage 4.4. I believe that I have > problems when I use something different from 0,1,2, for the name > of the vertices of a DiGraph.

Re: [sage-support] problem with viroable 2D arrays

2010-05-03 Thread Minh Nguyen
Hi, On Mon, May 3, 2010 at 11:17 PM, hamed akhavan wrote: > Please guide me, how can I do that in Sage? These threads from sage-support [1] and sage-devel [2] might be relevant. [1] http://groups.google.com/group/sage-support/browse_thread/thread/aa3f2adb5c2befed/ [2] http://groups.google

[sage-support] Re: systems of inequalities over the integers

2010-05-03 Thread Nathann Cohen
> I'm sure of the best way. You could just write your own > little function that checks the conditions for each > (i,j) in a big rectangle. Also, you might be able to use Sage's > MixedIntegerLinearProgram functionality. And here is how : p = MixedIntegerLinearProgram() x = p.new_variable() p.add

Re: [sage-support] systems of inequalities over the integers

2010-05-03 Thread David Joyner
On Mon, May 3, 2010 at 1:21 PM, David Joyner wrote: > On Mon, May 3, 2010 at 12:50 PM, Diego Ruano wrote: >> Thank you David for your answer. >> >> What about getting a solution over the integers? > > > I'm sure of the best way. You could just write your own To correct myself, I meant to say "I

[sage-support] Re: systems of inequalities over the integers

2010-05-03 Thread Jason Grout
On 05/03/2010 12:59 PM, Nathann Cohen wrote: I'm sure of the best way. You could just write your own little function that checks the conditions for each (i,j) in a big rectangle. Also, you might be able to use Sage's MixedIntegerLinearProgram functionality. And here is how : p = MixedIntegerLi

[sage-support] Re: systems of inequalities over the integers

2010-05-03 Thread Marshall Hampton
It's a hard problem in general. I think making a LattE optional package would help here. I have dim memories that perhaps Mike Hansen tried to make one once...ah yes: http://sage.math.washington.edu/home/mhansen/latte-1.2-mk-0.9.spkg ...but I'm not sure what shape that's in. A good paper descr