mjo/symbolic.py

   1 from sage.all import *
   2 from sage.interfaces.maxima_lib import maxima_lib
   3 from sage.symbolic.expression import Expression
   4
   5
   6 def set_simplification_domain(d):
   7     """
   8     Set Maxima's simplification domain.
   9
  10     INPUT:
  11
  12       - ``d`` -- The domain, either 'real' or 'complex'.
  13
  14     TESTS:
  15
  16     With the default 'complex' domain, we don't simplify this::
  17
  18         sage: sqrt(x^2).simplify()
  19         sqrt(x^2)
  20
  21     But in the 'real' domain, we do::
  22
  23         sage: set_simplification_domain('real')
  24         'real'
  25         sage: sqrt(x^2).simplify()
  26         abs(x)
  27         sage: set_simplification_domain('complex')
  28         'complex'
  29
  30     """
  31     cmd = 'domain: %s;' % d
  32     result = maxima_lib._eval_line(cmd)
  33     return result
  34
  35
  36 def safe_simplify(expr):
  37     """
  38     What should be a totally safe simplification operation that works
  39     a little better than the plain simplify().
  40
  41     Uses a top-level function because we can't monkey-patch Cython
  42     classes.
  43     """
  44     expr = expr.simplify_factorial()
  45     expr = expr.simplify_log()
  46     return expr