Changes between Initial Version and Version 6 of Ticket #5574


Ignore:
Timestamp:
10/19/15 13:58:56 (5 years ago)
Author:
rws
Comment:

This is a general shortcoming of AlgebraicNumber.__pow__():

sage: (QQbar(2)^3)^1.
...
TypeError: no canonical coercion from Real Field with 53 bits of precision to Rational Field

Legend:

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  • Ticket #5574

    • Property Summary changed from taking symbolic powers should coerce objects to symbolic expressions to AlgebraicNumber.__pow__() does only rational exponents
    • Property Report Upstream changed from to N/A
    • Property Component changed from symbolics to algebra
    • Property Milestone changed from sage-5.11 to sage-6.10
  • Ticket #5574 – Description

    initial v6  
    1 Reported by Alex Raichev on sage-support:
     1The first case reported by Alex Raichev on sage-support:
    22
    33{{{
     
    2525TypeError: no canonical coercion from New Symbolic Ring to Rational
    2626Field
     27
     28also:
     29
     30sage: (QQbar(2)^3)^1.
     31...
     32TypeError: no canonical coercion from Real Field with 53 bits of precision to Rational Field
    2733}}}
    2834
    29 Since pynac supports using arbitrary Sage objects as numeric objects in symbolic expressions, we should return a symbolic expression as a result of the above commands.
     35case 1: Since pynac supports using arbitrary Sage objects as numeric objects in symbolic expressions, we should return a symbolic expression as a result of the above commands.
     36
     37case 2: just coerce to CDF