[sage-devel] Re: absolute value in a p-adic quotient field
I would argue that P.root_field() should return a p-adic field here, not a polynomial quotient ring. This would be consistent with the behaviour of root_field for polynomials over QQ and number fields; generally, when we have a choice of several different Sage representations of the same mathematical object, it probably makes sense to return the one with the most functionality, doesn't it? I've opened a ticket for this change to root_field (#14893). David On Wednesday, July 10, 2013 10:49:54 PM UTC+1, Paul Mercat wrote: If I define 'a' like this: R.x=PolynomialRing(Qp(2)); P=2*x^2+1; K.a=P.root_field(); why 'a' has no attribute abs ? It's not a big problem, because it's easy to compute the absolute value from the norm, but it don't work : a.norm() gives TypeError: cannot construct an element of Full MatrixSpace of 2 by 2 dense matrices over 2-adic Field with capped relative precision 20 from [0, 1 + O(2^20), 2^-1 + 1 + 2 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7 + 2^8 + 2^9 + 2^10 + 2^11 + 2^12 + 2^13 + 2^14 + 2^15 + 2^16 + 2^17 + 2^18 + O(2^19), 0, O(2^20)]! Somebody knows why this don't work ? -- 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 http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/groups/opt_out.
[sage-devel] Re: absolute value in a p-adic quotient field
Well, the problem comes from a.matrix() which does not work. This is because it receives an incorrect number of terms, so it cannot build the matrix. In turn, this is because the length of (a**i).list() depends on i, which is maybe unexpected. I have not tried to look further. Frederic Le mercredi 10 juillet 2013 23:49:54 UTC+2, Paul Mercat a écrit : If I define 'a' like this: R.x=PolynomialRing(Qp(2)); P=2*x^2+1; K.a=P.root_field(); why 'a' has no attribute abs ? It's not a big problem, because it's easy to compute the absolute value from the norm, but it don't work : a.norm() gives TypeError: cannot construct an element of Full MatrixSpace of 2 by 2 dense matrices over 2-adic Field with capped relative precision 20 from [0, 1 + O(2^20), 2^-1 + 1 + 2 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7 + 2^8 + 2^9 + 2^10 + 2^11 + 2^12 + 2^13 + 2^14 + 2^15 + 2^16 + 2^17 + 2^18 + O(2^19), 0, O(2^20)]! Somebody knows why this don't work ? -- 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 http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/groups/opt_out.
Re: [sage-devel] Re: absolute value in a p-adic quotient field
This is http://trac.sagemath.org/sage_trac/ticket/13662 julian * Frédéric Chapoton fchapot...@gmail.com [2013-07-11 02:11:24 -0700]: Well, the problem comes from a.matrix() which does not work. This is because it receives an incorrect number of terms, so it cannot build the matrix. In turn, this is because the length of (a**i).list() depends on i, which is maybe unexpected. I have not tried to look further. Frederic Le mercredi 10 juillet 2013 23:49:54 UTC+2, Paul Mercat a écrit : If I define 'a' like this: R.x=PolynomialRing(Qp(2)); P=2*x^2+1; K.a=P.root_field(); why 'a' has no attribute abs ? It's not a big problem, because it's easy to compute the absolute value from the norm, but it don't work : a.norm() gives TypeError: cannot construct an element of Full MatrixSpace of 2 by 2 dense matrices over 2-adic Field with capped relative precision 20 from [0, 1 + O(2^20), 2^-1 + 1 + 2 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7 + 2^8 + 2^9 + 2^10 + 2^11 + 2^12 + 2^13 + 2^14 + 2^15 + 2^16 + 2^17 + 2^18 + O(2^19), 0, O(2^20)]! Somebody knows why this don't work ? -- 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 http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/groups/opt_out. pgpYzHCAXSDn2.pgp Description: PGP signature
