This is certainly a bug: sage: a = sqrt(-3) sage: a sqrt(-3) sage: a.conjugate() sqrt(-3)
sage: bool(a==a.conjugate()) True But I have no idea where to look for it, since symbolic expressions are a mystery to me! John On 26 April 2010 20:48, Gonzalo Tornaria <torna...@math.utexas.edu> wrote: > On Mon, Apr 26, 2010 at 4:26 PM, John Cremona <john.crem...@gmail.com> wrote: >> In number theory it is very useful to have this norm-alisation, as >> well as the square root one also called abs. It's a special case of >> the algebraic concept of norm(a) = product of conjugates of a. > > And the determinant of the action of a on C (as an R-vector space of > dimension 2) by complex multiplication. > > However, this doesn't seem correct: > > sage: sqrt(-3).norm() > -3 > > (I think the problem is with conjugates) > > --- > > Anyhow, the norm for complex numbers is fine as is, but for the > symbolic ring, it makes me uneasy, e.g. > > sage: SR(2).norm() > 4 > sage: CC(2).norm() > 4.00000000000000 > sage: QQ(2).norm() > 2 > sage: ZZ(2).norm() > ... > AttributeError: 'sage.rings.integer.Integer' object has no attribute 'norm' > sage: RR(2).norm() > ... > AttributeError: 'sage.rings.real_mpfr.RealNumber' object has no attribute > 'norm' > > > Gonzalo > > -- > To post to this group, send an email to sage-devel@googlegroups.com > To unsubscribe from this group, send an email to > sage-devel+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/sage-devel > URL: http://www.sagemath.org > -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
