On 12 April 2014 00:06, Robert Bradshaw <rober...@gmail.com> wrote: > Note that this is implemented in various places, e.g. > https://github.com/sagemath/sagelib/blob/master/sage/ext/multi_modular.pyx > , but certainly a general user-friendly function would be nice to > have.
Agreed. In my post I was mainly trying to make sure that the implementation was not done via the obvious induction / recursion, as that is well known to provide very skewed solutions. If one wants to get a small solution then using LLL is also possible. John > > On Fri, Apr 11, 2014 at 1:18 PM, John Cremona <john.crem...@gmail.com> wrote: >> On 11 April 2014 19:33, Kannappan Sampath <kntri...@gmail.com> wrote: >>> >>> On Fri, Apr 11, 2014 at 11:03 PM, David Roe <roed.m...@gmail.com> wrote: >>>> >>>> Sounds like a good suggestion. Do you want to create a trac account so >>>> that you can create the ticket? >>>> David >>> >>> >>> I recall having created trac account for François. >>> >>> -KnS >>> >>>> >>>> On Fri, Apr 11, 2014 at 9:24 AM, François Colas <fco...@gmail.com> wrote: >>>>> >>>>> Hello group, >>>>> >>>>> I realised that extended GCD for several integers is not implemented in >>>>> Sage (i.e. xgcd2([a1, ..., an])) >>>>> >>>>> Actually this feature already exists in Magma : >>>>> >>>>> > ExtendedGreatestCommonDivisor([385, 231, 165, 105]); >>>>> 1 [ -2, 1, 2, 2 ] >>>>> >>>>> It could be interesting to have something like : >>>>> >>>>> g, u = xgcd2([a1, ..., an]) >>>>> >>>>> with u such that : >>>>> >>>>> a1*u1 + ... + an*un = g >> >> Here is how I would implement it: >> >> sage: v = [385, 231, 165, 105] >> sage: _,_,U = Matrix(v).smith_form() >> sage: U.column(0) >> (-38, 76, -19, 2) >> sage: U.column(0) * vector(v) >> 1 >> >> >>>>> >>>>> Do you think a new ticket could be posted? >>>>> >>>>> Thanks, >>>>> >>>>> François >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google Groups >>>>> "sage-devel" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send an >>>>> email to sage-devel+unsubscr...@googlegroups.com. >>>>> To post to this group, send email to sage-devel@googlegroups.com. >>>>> Visit this group at http://groups.google.com/group/sage-devel. >>>>> For more options, visit https://groups.google.com/d/optout. >>>> >>>> >>>> -- >>>> You received this message because you are subscribed to the Google Groups >>>> "sage-devel" group. >>>> To unsubscribe from this group and stop receiving emails from it, send an >>>> email to sage-devel+unsubscr...@googlegroups.com. >>>> To post to this group, send email to sage-devel@googlegroups.com. >>>> Visit this group at http://groups.google.com/group/sage-devel. >>>> For more options, visit https://groups.google.com/d/optout. >>> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "sage-devel" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to sage-devel+unsubscr...@googlegroups.com. >>> To post to this group, send email to sage-devel@googlegroups.com. >>> Visit this group at http://groups.google.com/group/sage-devel. >>> For more options, visit https://groups.google.com/d/optout. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "sage-devel" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to sage-devel+unsubscr...@googlegroups.com. >> To post to this group, send email to sage-devel@googlegroups.com. >> Visit this group at http://groups.google.com/group/sage-devel. >> For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to the Google Groups > "sage-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-devel+unsubscr...@googlegroups.com. > To post to this group, send email to sage-devel@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-devel. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
