#10978: Resultant for polynomials over RDF and CDF not implemented
----------------------------+-----------------------------------------------
Reporter: spice | Owner: AlexGhitza
Type: defect | Status: new
Priority: major | Milestone: sage-4.7
Component: algebra | Keywords: polynomial, resultant
Author: Simon Spicer | Upstream: N/A
Reviewer: | Merged:
Work_issues: |
----------------------------+-----------------------------------------------
Calling the resultant method for a polynomial defined over RDF or CDF
returns a NotImplementedError. It would appear that this results from it
not being implemented in Singular.
{{{
sage: R.<x> = PolynomialRing(CDF)
sage: f = R(1 - I*x + (0.5)*x^2 + (1.7)*x^3)
sage: g = f.derivative()
sage: f.resultant(g)
---------------------------------------------------------------------------
TypeError Traceback (most recent call
last)
/Users/simonspicer/<ipython console> in <module>()
/Users/simonspicer/sage/local/lib/python2.6/site-
packages/sage/rings/polynomial/polynomial_singular_interface.pyc in
resultant(self, other, variable)
351 return lcm_func(self, singular, have_ring)
352 def resultant(self, other, variable=None):
--> 353 return resultant_func(self, other, variable)
354
355 def _singular_func(self, singular=singular_default,
have_ring=False):
/Users/simonspicer/sage/local/lib/python2.6/site-
packages/sage/rings/polynomial/polynomial_singular_interface.pyc in
resultant_func(self, other, variable)
499 if variable is None:
500 variable = self.parent().gen(0)
--> 501 rt = self._singular_().resultant(other._singular_(),
variable._singular_())
502 r = rt.sage_poly(self.parent())
503 if self.parent().ngens() <= 1 and r.degree() <= 0:
/Users/simonspicer/sage/local/lib/python2.6/site-
packages/sage/interfaces/expect.pyc in __call__(self, *args, **kwds)
1481
1482 def __call__(self, *args, **kwds):
-> 1483 return self._obj.parent().function_call(self._name,
[self._obj] + list(args), kwds)
1484
1485 def help(self):
/Users/simonspicer/sage/local/lib/python2.6/site-
packages/sage/interfaces/expect.pyc in function_call(self, function, args,
kwds)
1380 [s.name() for s in args],
1381 ['%s=%s'%(key,value.name())
for key, value in kwds.items()])
-> 1382 return self.new(s)
1383
1384 def _function_call_string(self, function, args, kwds):
/Users/simonspicer/sage/local/lib/python2.6/site-
packages/sage/interfaces/expect.pyc in new(self, code)
1161
1162 def new(self, code):
-> 1163 return self(code)
1164
1165
###################################################################
/Users/simonspicer/sage/local/lib/python2.6/site-
packages/sage/interfaces/singular.pyc in __call__(self, x, type)
659 x = str(x)[1:-1]
660
--> 661 return SingularElement(self, type, x, False)
662
663 def has_coerce_map_from_impl(self, S):
/Users/simonspicer/sage/local/lib/python2.6/site-
packages/sage/interfaces/singular.pyc in __init__(self, parent, type,
value, is_name)
1122 except (RuntimeError, TypeError, KeyboardInterrupt),
x:
1123 self._session_number = -1
-> 1124 raise TypeError, x
1125 else:
1126 self._name = value
TypeError: Singular error:
? not implemented
? error occurred in or before STDIN line 94: `def
sage19=resultant(sage17,sage18,sage15);`
}}}
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/10978>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
