> 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 >
I'm looking for a linear relation with coefficients in K(x), so you probably mean linear algebra over K(x) ? to be clear : i know there is at least a relation P_0(x) + P_1(x) f + P_2(x) f^2 + ... + P_d(x) f^d where d is known, and I'm looking for the Pi's, which are polynomials. When d = 1 this is the same as saying that i know that f is rational, and that i want to write it explicitly as a fraction P(x)/Q(x), exactly as in your other post. am I missing something? Pierre 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...@googlegroups.com <javascript:>. > > To post to this group, send email to sage-s...@googlegroups.com > <javascript:>. > > 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.
