Thanks for the bug report! The default way to compute height of points on elliptic curves over Q is to call the pari library, and that has been updated between the version you mention. Somehow that update has broken this, and I will look into it.
If you say point.height(algorithm='sage') then it does not call the pari library but instead uses native Sage code, which I wrote. I am running that now: the method used is not brilliant (it's the algorithm from Silverman's paper, which is not so good for very large inputs). Work in progress is to implement the better AGM method of Mestre. I see that Peter Bruin is also replying, so I will leave it there. John Cremona On 26 November 2014 at 19:18, <[email protected]> wrote: > Hi, > > In the latest version of sage 6.4.1 the following code failed. > I didn't have any problem with 6.2 version of sage. > > sage: > U=[-245369975623514803521420211420402474815373720177518420696215292670924086780233779586506792145074717/4069861969699146045958032034788970995470603578576, > > -696053034387689435413673877713244121475782562610666903528251447608130654196417305610237634015759861/4069861969699146045958032034788970995470603578576, > -49356694805693369953216822105035107974083562942605713355717183776373331122267882948881129025418396548321363993080002121985116427859996985649385099335/4069861969699146045958032034788970995470603578576, > 5996724761485351384753083917633373954904218466995628499407992841502416127074022935350022919212488198205525833829916828282709837728834438536000230267/1017465492424786511489508008697242748867650894644, > -1943033527672518505867347410801184866534773028979571976479290969993491996577167508758887358085512124817167326269402804641328588524702957475568608101932310746684310251168033629279636817525659690186705/4069861969699146045958032034788970995470603578576] > sage: E=EllipticCurve(QQ,U); > sage: point=E([283188771261789732541662405743402980051199109235, > 39175522019721182331498476245534716069785193060995, 1]); > sage: point.height(); > > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > File "_sage_input_8.py", line 10, in <module> > exec compile(u'open("___code___.py","w").write("# -*- coding: utf-8 > -*-\\n" + > _support_.preparse_worksheet_cell(base64.b64decode("cG9pbnQuaGVpZ2h0KCk7"),globals())+"\\n"); > execfile(os.path.abspath("___code___.py")) > File "", line 1, in <module> > > File "/tmp/tmpSQSeuN/___code___.py", line 2, in <module> > exec compile(u'point.height(); > File "", line 1, in <module> > > File > "/usr/lib/sagemath/local/lib/python2.7/site-packages/sage/schemes/elliptic_curves/ell_point.py", > line 2655, in height > h = Emin.pari_curve().ellheight(P, precision=precision) > File "sage/libs/pari/gen.pyx", line 6051, in > sage.libs.pari.gen.gen.ellheight > (build/cythonized/sage/libs/pari/gen.c:29422) > File "sage/libs/pari/handle_error.pyx", line 90, in > sage.libs.pari.handle_error._pari_handle_exception > (build/cythonized/sage/libs/pari/handle_error.c:1112) > sage.libs.pari.gen.PariError: unknown type 0 > > > Sage failed to compute the canonical height. > any ideas? > > K.D. > > -- > 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 [email protected]. > To post to this group, send email to [email protected]. > 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
