#19288: Make real/complex number field embeddings more accurate
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       Reporter:  pbruin          |        Owner:
           Type:  enhancement     |       Status:  new
       Priority:  minor           |    Milestone:  sage-6.9
      Component:  number fields   |   Resolution:
       Keywords:                  |    Merged in:
        Authors:  Jeroen Demeyer  |    Reviewers:
Report Upstream:  N/A             |  Work issues:
         Branch:                  |       Commit:
   Dependencies:                  |     Stopgaps:
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Comment (by pbruin):

 I don't completely agree with re-purposing this ticket.  In my opinion a
 method `logabs()` would still be useful.  It should implement ''x'' ↦ log
 |''x''|,,v,, for any place ''v'': either an Archimedean place defined by a
 real or complex embedding, or a non-Archimedean place defined by a prime
 ideal of the ring of integers.  For Archimedean places it would do this by
 simply computing the embedding to sufficient precision and then taking the
 logarithm of the absolute value.  For non-Archimedean places it should
 return `-x.valuation(p) * RR(p.norm()).log()`, which would presumably be
 more efficient than `RR(p.norm()^-x.valuation(p)).log()`.

 Anyway, I'm not going to do that now, so I don't mind too much if this
 becomes the ticket for fixing the accuracy of real/complex embeddings.
 Still, I would be in favour of having a `logabs()` method at some point
 (on a different ticket).

--
Ticket URL: <http://trac.sagemath.org/ticket/19288#comment:7>
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