Changes between Version 19 and Version 20 of Ticket #16587


Ignore:
Timestamp:
07/06/15 15:07:15 (6 years ago)
Author:
rws
Comment:

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  • Ticket #16587

    • Property Summary changed from f(expr).n() fails for all generalized functions to f(expr,hold).n() fails for all generalized functions
  • Ticket #16587 – Description

    v19 v20  
    1 As reported in http://ask.sagemath.org/question/8535/problem-with-sign-sgn-and-n/ by Louis Cypher:
     1{{{
     2sage: M = sgn((3/2),hold=True); M.n()
     3...
     4TypeError: cannot evaluate symbolic expression numerically
     5sage: polylog(2.,.9).n()
     6...
     7TypeError: cannot evaluate symbolic expression numerically
     8
     9}}}
     10The original problem is now resolved, it was reported in http://ask.sagemath.org/question/8535/problem-with-sign-sgn-and-n/ by Louis Cypher:
    211{{{
    312sage: M = sgn(cos(3/2))
     
    1423
    1524Problem seems to be that in `M.n??` we see that it's looking for `is_a_numeric(x._gobj)` but apparently that fails, as does the constant, so it thinks we are looking at evaluating `sgn(cos(x))` instead of `sgn(cos(3/2))`.
    16 
    17 UPDATE:
    18 The problem also appears with `polylog(2.,.9).n()` for example.