[sage-support] Re: Solving recursion formula?

2018-12-14 Thread Marc Mezzarobba
Hi Simon, Simon King wrote: > Coincidentally, William Stein today advertised a multi author book on > doing computations with Sage, and it has a chapter on solving > recurrences, also pointing to sympy. Well, I'm not responsible for that part ;-) -- Marc -- You received this message because y

[sage-support] Re: Solving recursion formula?

2018-12-09 Thread Marc Mezzarobba
Simon King wrote: > What about > a more complicated recurrence, such as the one given by > x_(n+1) = 1 + x_n*2/n > Any chances to solve those and similar recurrences automatically? You can try sympy's rsolve() or Maxima's solve_rec(). I don't know how powerful they are. -- Marc -- You receive

[sage-support] Re: Solving recursion formula?

2018-12-08 Thread Marc Mezzarobba
Simon King wrote: > That's not what I am looking for. No data are given. Given is some > recursion formula; what we want to know is a corresponding closed > formula. Example: The recursion x_0=1 and x_(n+1) := f(x_n) = 2*x_n > should result in the closed formula x_n = 2^n. ore_algebra also has som

[sage-support] Issue compiling Cython code that uses Sage

2018-03-15 Thread Marc Mezzarobba
Hi, Can anyone explain why the following works: - 8< - 8< - 8< - 8< - 8< - 8< - 8< - 8< - $ ~/co/sage/sage --version SageMath version 8.2.beta8, Release Date: 2018-03-10 $ head foo.pyx setup.py ==> foo.pyx <== from sage.libs.gmp.types cimport mpz_t ==> setup.

[sage-support] Re: Displaying graphics from a Sage script

2017-01-14 Thread Marc Mezzarobba
John H Palmieri wrote: > This question comes from > http://stackoverflow.com/questions/41638257/graphics-in-sage-script: > if I have a file "foo.sage" and I want to run "sage foo.sage" and have > it pop up a window displaying a plot, how do I do this? Running sage < foo.sage instead of sage foo.sa

[sage-support] Re: embedding of number field element encapseled in symbolic ring

2017-01-09 Thread Marc Mezzarobba
Nils Bruin wrote: > If a field embeds into QQbar, then there should be an implied coercion > into CC, though: QQbar as implemented in sage is a subfield of the > field of complex numbers (as you can see from how the elements print). Let me add that there are long-standing tickets (#5355, #12715) f

[sage-support] Re: splitting field vs. Galois closure

2017-01-08 Thread Marc Mezzarobba
Simon King wrote: > Wouldn't it be better to [...] or change the > arithmetic operations by *avoiding* a call to __init__()? That's what the branch I pointed to tries to do, to some extent at least. But the structure of generic polynomial classes (with many operations implemented in an abstract

[sage-support] Re: splitting field vs. Galois closure

2017-01-07 Thread Marc Mezzarobba
Nils Bruin wrote: > polynomial aritmetic over ZZ and QQ is so much more optimized than > over number fields, Yes, polynomial arithmetic over number fields is painfully slow. The branch trac:u/mmezzarobba/speed_up_generic_polynomials (not fully tested yet) may help a little. Another trick you ca

[sage-support] Re: Multivariate division with remainder of polynomials

2016-03-31 Thread Marc Mezzarobba
als must predate the introduction of Groebner bases in Sage... -- Marc Mezzarobba -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@goo

[sage-support] Re: Re: Multivariate division with remainder of polynomials

2016-03-31 Thread Marc Mezzarobba
Jeroen Demeyer wrote: > Is there any reason that quo_rem is not consistent with .mod()? That > is no longer arbitrary and would also extend the Euclidean division of > univariate polynomials. Not quite: you'd have to return a tuple of quotients. -- Marc Mezzarobba -- You receive

[sage-support] Re: Multivariate division with remainder of polynomials

2016-03-30 Thread Marc Mezzarobba
for exact divisions or divisions by monomials...) > Is multivariate division in the sense of > https://en.wikipedia.org/wiki/Gr%C3%B6bner_basis#Reduction implemented > somewhere in Sage? Yes: p.mod(ideal) or ideal.reduce(p). -- Marc Mezzarobba -- You received this message because you are

[sage-support] Re: Conversion to float taking forever

2014-10-10 Thread Marc Mezzarobba
Nico Van Cleemput wrote: > Looking at the implementation of the > float conversion, the problem seems to come from the following: > > sage: AA(ge) So apparently Sage is trying to prove that the imaginary part of the algebraic result is exactly zero. > Is there another way to get a good float ap

[sage-support] Re: finding and contacting an author of a function ?

2014-02-24 Thread Marc Mezzarobba
Hi Dror, dror fidler wrote: > i recently used is_distance_regular() in the graph package. > however the definition of the function in the documentation page does > not fit the definition of distance regular graphs. i would be very > interested to find the source of the information the author used

[sage-support] Re: bug/feature in subs() for polynomials in a polynomial ring over a polynomial ring

2014-02-17 Thread Marc Mezzarobba
Dima Pasechnik wrote: > sage: r0=QQ['a1,a2'] > sage: a1,a2=r0.gens() > sage: r=r0['x1,x2'] [...] > I am using such a ring as I want to treat ai as parameters, i.e. I > would like monomial expansions in xi alone. > Perhaps there is a better way to accomplish this? The best I can think of is p.map_

[sage-support] Re: trouble with polynomial functions, change of variables, and coefficients

2010-07-21 Thread Marc Mezzarobba
fficients() functions. I think I'm not doing a good job with > difference between symbolic expressions, functions, and polynomials. I think what you want is to replace the first line by R. = PolynomialRing(SR, 2) Then the elements of R will be allowed to contain symbolic variabl

[sage-support] Re: power series --> rational function conversion?

2010-06-26 Thread Marc Mezzarobba
for polynomials, not power series: sage: x = polygen(GF(17)) sage: (1-x+x^2-x^3).rational_reconstruct(x^4, 1, 1) (1, x + 1) -- Marc Mezzarobba -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroup

[sage-support] Re: Is it possible to generate the documentation in any other language than English

2010-06-21 Thread Marc Mezzarobba
at http://www.sagemath.fr/ I am sending you a more detailed reply in French (this is much easier for me) off-list. -- Marc Mezzarobba -- 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 mor