On Friday, October 7, 2016 at 1:00:08 PM UTC+2, Clemens Heuberger wrote: > > > I was surprised by the following behaviour: > > sage: gamma(QQbar(sqrt(2))) > 0.886581428719259 > sage: gamma(QQbar(sqrt(2))).parent() > Complex Field with 53 bits of precision > > (I would have preferred to have some symbolic answer or at least an answer > in > CIF, but not in CC) >
There seems to be no way to effectively guarantee "What goes in goes out (at least nearly)" except writing a dedicated QQbar.gamma() member function. OTOH as soon as you return something other than QQbar from such a member purists will roast you. CIF doesn't have gamma() either but usage of CIF should be rethought in the light of sage: ComplexBallField(100)(sqrt(2)).gamma() [0.8865814287192591250809176124 +/- 2.00e-29] Really, arb functionality and integration does not leave much to desire, so use it. As to a possible symbolic result (is there one?) this could be added to the symbolic gamma(). > Furthermore: > > sage: gamma(QQbar(1/2)) > Traceback (most recent call last): > ... > TypeError: no canonical coercion from Algebraic Field to Rational Field > That seems a genuine bug. -- 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 https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
