On 2 April 2015 at 16:13, Pierre <pierre.guil...@gmail.com> wrote: > Hi, > > I have a power series f in K[[x]] where K is a finite field, and I know that > it is algebraic over K(x). I'm looking for an explicit polynomial P in K[x, > y] such that P(x, f) = 0. I can figure out a bound for the degree of P in y, > in my example (though not in x).
Given a degree bound d in y, you are looking for a linear relation between 1, f, f^2, ..., f^d, which you could find using linear algebra over K after making sure that you have at least d+1 coefficients for each power of f. I have done something similar where K was a number field of quite large degree and d was about 200, so I'm sure it is possible in your case. If you post code which produces your f and d then someone will surely post code which soves the problem! (I am not volunteering though.) John Cremona > > Given this post > > https://groups.google.com/forum/#!searchin/sage-support/power$20series/sage-support/hcH-mtERhHg/bo4xG1sNs5kJ > > I doubt that Sage can do this out of the box. I would be grateful though for > any tips on existing sage functionality that would help with my problem. > > If anyone thinks this is hopelessly hard, by the way, please let me know ! > (I myself haven't got an intuition yet for how difficult this is.) > > Thanks ! > > Pierre > > -- > 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...@googlegroups.com. > To post to this group, send email to sage-support@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-support. > For more options, visit https://groups.google.com/d/optout. -- 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...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
