Re: [sage-support] Fourier–Motzkin elimination

2011-01-26 Thread Philipp Schneider
Am 24.01.11 07:47, schrieb tvn: > hi, just wondering if the Fourier-Motzkin algorithm for eliminating > variable from a system of linear inequalities is implemented somewhere in > Sage ? > Hi, it shouldn't be too hard to implement Fourier-Motzkin elemimination yourself. Here is the definition

[sage-support] German translation of the tutorial / Übersetzung des Tutorials in Deutsch

2010-10-04 Thread Philipp Schneider
://wwwcip.informatik.uni-erlangen.de/~snphschn/sage/doc/output/pdf/de/tutorial/ You can either send me the corrections per email, or you can post them to sage trac at: http://trac.sagemath.org/sage_trac/ticket/9725 Thank you, Philipp Schneider Liebe Sage-Community, Michael Mardaus und ich sind glücklich

Re: [sage-support] finite cartesian product

2010-10-03 Thread Philipp Schneider
Hi, > (...) > In my next try I used FiniteEnumeratedSet and cartesian_product, but > this is not iterable. > Is there any other way to do this? there is a sage function called "cartesian_product_iterator". Greetings, Phil -- To post to this group, send email to sage-support@googlegroups.com To

Re: [sage-support] Two basic questions

2010-09-05 Thread Philipp Schneider
Hi, > Q2. How can I define the set of all primes up to some limit N but > excluding 2 and multiples of some number D? Try this: sage: N=100 sage: D=5 sage: [i for i in primes(3,N+1) if not i.divides(D)] [3, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97] Gr

Re: [sage-support] Two basic questions

2010-09-05 Thread Philipp Schneider
Hi, > Q1. How can I extract elements from a solution set? > > For example, consider: > > sage: x, y = var('x, y') > sage: solve([x+y==6, x-y==4], x, y) > [[x == 5, y == 1]] Like this: sage: sol = solve([x+y==6, x-y==4], x, y) sage: sol[0] [x == 5, y == 1] sage: sol[0][0] x == 5 sage: sol[0][0].r

Re: [sage-support] Re: symbolic calculation with roots of a polynomial of degree >= 5

2010-08-15 Thread Philipp Schneider
Nils, thanks for you answer. > Basically, the answer to "How do I compute explicitly with the > conjugates of an algebraic number" is "Don't". Actually I'm just trying to convert an example from mathematica/maple to sage. Both give me the answer instantaneously. Mathematica: In[1] := s = Solve[

[sage-support] symbolic calculation with roots of a polynomial of degree >= 5

2010-08-15 Thread Philipp Schneider
Hi, I'm trying to symbolically calculate the product of all roots of the polynomial x^5 - 3*x -1. (The answer should of course be 1). Numerically I can compute the product as follows: sage: x = polygen(QQbar) sage: p=x^5-3*x-1 sage: p.roots(QQbar) [(-1.214648042698462?, 1), (-0.3347341419433527?,

[sage-support] Re: Weird matrix bug

2010-08-14 Thread Philipp Schneider
On Jul 23, 9:36 pm, Jason Grout wrote: > On 7/23/10 11:35 AM, VictorMiller wrote: > > > There's abugin assigning 1 x 1 submatrices.  assigning any > > submatrices with dimensions bigger than 1 seems to work as expected: > > >sage: A =matrix(GF(2),100,100) > >sage: C1 =matrix(GF(2),[[1]]) > >sage: