Hello,
Yay, that worked!!! I needed to create and appropriately assign the
attribute Element to this class.
Thank you! :)
I'm attaching the updated error file now.
Arpit.
On 20 June 2016 at 00:45, Vincent Delecroix <[email protected]>
wrote:
> You might want to read
>
>
> http://doc.sagemath.org/html/en/thematic_tutorials/coercion_and_categories.html#coercion-and-categories
>
> I answer to your specific questions below.
>
>
> On 19/06/16 21:08, Arpit Merchant wrote:
>
>>
>>>
>>> 1 class MyElement(Element):
>>> 2 ...
>>> 3
>>> 4 class MyParent(Parent):
>>> 5 Element = MyElement
>>> 6
>>> 7 def __init__(self, ...):
>>> 8 ...
>>> 9 Parent.__init__(self, ...)
>>>
>>> I'm not sure I understand what you mean. Could you please elaborate
>>>
>>>> a little?
>>>>
>>>>
>>> The attribute `element_class` of parents is created during the parent
>>> constructor, i.e. the __init__. It creates with dynamical inheritance a
>>> new class "element_class" which will inherits new methods depending of
>>> the category of your parent.
>>>
>>> In order to work, there should be an attribute "Element" available (line
>>> 5
>>> in the above snippet). Your
>>> class `CenterSkewPolynomialRing` is a parent that modelizes a set. It
>>> either inherits from Parent, or Ring or something similar. And the
>>> objects
>>> that belong to it should inherit from Element or RingElement or something
>>> similar.
>>>
>>>
>>> Just to restate, MyParent here is CenterSkewPolynomialRing which inherits
>> from class PolynomialRing_general which inherits from
>> sage.algebras.algebra.Algebra. Indeed, the constructor of
>> CenterSkewPolynomialRing takes `element_class` as input (which by default,
>> is None).
>>
>
> What are you doing with this element_class from the input? The only
> reasonable thing would be
>
> def __init__(self, element_class, ...):
> self.Element = element_class
> Algebra.__init__(self, ...)
>
> But the name "element_class" is confusing because of the
> category/parent/element logic that takes the attribute Element to build a
> new attribute named element_class.
>
> What does MyElement represent in your example? What is its connection to
>> MyParent?
>>
>
> In the context of PolynomialRing (as a parent) it would be Polynomial.
>
> And since Element is itself a class, won't writing Element = MyElement give
>> a syntax error?
>>
>
> No. These belong to very different things. There is the Element class and
> here you are creating an attribute of a class named Element.
>
>
> Vincent
>
> --
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too few successful tests, not using stored timings
Running doctests with ID 2016-06-20-00-59-25-8e75afbe.
Git branch: apply_skew_polynomials_patch
Using --optional=mpir,python2,sage
Doctesting 1 file.
sage -t src/sage/rings/polynomial/skew_polynomial_ring.py
**********************************************************************
File "src/sage/rings/polynomial/skew_polynomial_ring.py", line 589, in
sage.rings.polynomial.skew_polynomial_ring.SkewPolynomialRing_general.twist_map
Failed example:
S.twist_map(-1)
Expected:
Traceback (most recent call last):
...
NotImplementedError
Got:
<BLANKLINE>
Traceback (most recent call last):
File
"/home/arpit/Documents/GSOC_16/sage-7.2/local/lib/python2.7/site-packages/sage/doctest/forker.py",
line 496, in _run
self.compile_and_execute(example, compiler, test.globs)
File
"/home/arpit/Documents/GSOC_16/sage-7.2/local/lib/python2.7/site-packages/sage/doctest/forker.py",
line 858, in compile_and_execute
exec(compiled, globs)
File "<doctest
sage.rings.polynomial.skew_polynomial_ring.SkewPolynomialRing_general.twist_map[6]>",
line 1, in <module>
S.twist_map(-Integer(1))
File
"/home/arpit/Documents/GSOC_16/sage-7.2/local/lib/python2.7/site-packages/sage/rings/polynomial/skew_polynomial_ring.py",
line 605, in twist_map
map = self._map**n
File "sage/categories/map.pyx", line 1264, in
sage.categories.map.Map.__pow__
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/categories/map.c:8985)
return generic_power(self, n)
File "sage/structure/element.pyx", line 3671, in
sage.structure.element.generic_power
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/element.c:28593)
return generic_power_c(a,n,one)
File "sage/structure/element.pyx", line 3704, in
sage.structure.element.generic_power_c
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/element.c:29266)
a = ~a
TypeError: bad operand type for unary ~:
'sage.rings.morphism.RingHomomorphism_im_gens'
**********************************************************************
File "src/sage/rings/polynomial/skew_polynomial_ring.py", line 995, in
sage.rings.polynomial.skew_polynomial_ring.SkewPolynomialRing_general.centre
Failed example:
a = (3*t^2 + 4*t + 6)*x^2 + (2*t + 1)*x + 3*t^2 + 6*t + 4
Exception raised:
Traceback (most recent call last):
File
"/home/arpit/Documents/GSOC_16/sage-7.2/local/lib/python2.7/site-packages/sage/doctest/forker.py",
line 496, in _run
self.compile_and_execute(example, compiler, test.globs)
File
"/home/arpit/Documents/GSOC_16/sage-7.2/local/lib/python2.7/site-packages/sage/doctest/forker.py",
line 858, in compile_and_execute
exec(compiled, globs)
File "<doctest
sage.rings.polynomial.skew_polynomial_ring.SkewPolynomialRing_general.centre[7]>",
line 1, in <module>
a = (Integer(3)*t**Integer(2) + Integer(4)*t +
Integer(6))*x**Integer(2) + (Integer(2)*t + Integer(1))*x +
Integer(3)*t**Integer(2) + Integer(6)*t + Integer(4)
File "sage/structure/element.pyx", line 1798, in
sage.structure.element.RingElement.__mul__
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/element.c:16351)
return coercion_model.bin_op(left, right, mul)
File "sage/structure/coerce.pyx", line 1020, in
sage.structure.coerce.CoercionModel_cache_maps.bin_op
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/coerce.c:8743)
action = self.get_action(xp, yp, op, x, y)
File "sage/structure/coerce.pyx", line 1557, in
sage.structure.coerce.CoercionModel_cache_maps.get_action
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/coerce.c:15560)
action = self.discover_action(R, S, op, r, s)
File "sage/structure/coerce.pyx", line 1697, in
sage.structure.coerce.CoercionModel_cache_maps.discover_action
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/coerce.c:17010)
action = (<Parent>R).get_action(S, op, True, r, s)
File "sage/structure/parent.pyx", line 2742, in
sage.structure.parent.Parent.get_action
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/parent.c:21612)
action = self.discover_action(S, op, self_on_left, self_el, S_el)
File "sage/structure/parent.pyx", line 2818, in
sage.structure.parent.Parent.discover_action
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/parent.c:22849)
action = detect_element_action(self, S, self_on_left, self_el, S_el)
File "sage/structure/coerce_actions.pyx", line 230, in
sage.structure.coerce_actions.detect_element_action
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/coerce_actions.c:5232)
return (RightModuleAction if X_on_left else LeftModuleAction)(Y, X, y,
x)
File "sage/structure/coerce_actions.pyx", line 339, in
sage.structure.coerce_actions.ModuleAction.__init__
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/coerce_actions.c:6087)
self.extended_base = pushout(G, S)
File
"/home/arpit/Documents/GSOC_16/sage-7.2/local/lib/python2.7/site-packages/sage/categories/pushout.py",
line 3667, in pushout
while len(Ss) > 0 and Rs[-1].has_coerce_map_from(Ss[-1]):
File "sage/structure/parent.pyx", line 2238, in
sage.structure.parent.Parent.has_coerce_map_from
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/parent.c:17921)
cpdef bint has_coerce_map_from(self, S) except -2:
File "sage/structure/parent.pyx", line 2260, in
sage.structure.parent.Parent.has_coerce_map_from
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/parent.c:17871)
return self._internal_coerce_map_from(S) is not None
File "sage/structure/parent.pyx", line 2400, in
sage.structure.parent.Parent._internal_coerce_map_from
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/parent.c:18788)
mor = self.discover_coerce_map_from(S)
File "sage/structure/parent.pyx", line 2591, in
sage.structure.parent.Parent.discover_coerce_map_from
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/parent.c:19948)
mor = mor * connecting
File "sage/categories/map.pyx", line 906, in
sage.categories.map.Map.__mul__
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/categories/map.c:7354)
return self._composition(right)
File "sage/categories/map.pyx", line 947, in
sage.categories.map.Map._composition
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/categories/map.c:7606)
return self._composition_(right, H)
File "sage/rings/morphism.pyx", line 786, in
sage.rings.morphism.RingHomomorphism._composition_
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/rings/morphism.c:5895)
return homset([self(g) for g in right.im_gens()], False)
File
"/home/arpit/Documents/GSOC_16/sage-7.2/local/lib/python2.7/site-packages/sage/rings/homset.py",
line 263, in __call__
return morphism.RingHomomorphism_from_quotient(self, phi)
File "sage/rings/morphism.pyx", line 1749, in
sage.rings.morphism.RingHomomorphism_from_quotient.__init__
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/rings/morphism.c:12757)
if phi(x) != 0:
File "sage/categories/map.pyx", line 780, in
sage.categories.map.Map.__call__
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/categories/map.c:6329)
return self._call_(x)
File "sage/rings/morphism.pyx", line 1243, in
sage.rings.morphism.RingHomomorphism_im_gens._call_
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/rings/morphism.c:9393)
return x._im_gens_(self.codomain(), self.im_gens())
File "sage/rings/integer.pyx", line 769, in
sage.rings.integer.Integer._im_gens_
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/rings/integer.c:7037)
return codomain._coerce_(self)
File "sage/structure/parent_old.pyx", line 239, in
sage.structure.parent_old.Parent._coerce_
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/parent_old.c:4547)
return self.coerce(x)
File "sage/structure/parent.pyx", line 1351, in
sage.structure.parent.Parent.coerce
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/structure/parent.c:11131)
return (<map.Map>mor)._call_(x)
File "sage/categories/map.pyx", line 1697, in
sage.categories.map.FormalCompositeMap._call_
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/categories/map.c:11365)
x = f._call_(x)
File "sage/rings/polynomial/skew_polynomial_element.pyx", line 3095, in
sage.rings.polynomial.skew_polynomial_element.SkewPolynomialBaseringInjection._call_
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/rings/polynomial/skew_polynomial_element.c:26051)
cpdef Element _call_(self, x):
File "sage/rings/polynomial/skew_polynomial_element.pyx", line 3096, in
sage.rings.polynomial.skew_polynomial_element.SkewPolynomialBaseringInjection._call_
(/home/arpit/Documents/GSOC_16/sage-7.2/src/build/cythonized/sage/rings/polynomial/skew_polynomial_element.c:25999)
return self._new_constant_poly_(x, self._codomain)
TypeError: 'NoneType' object is not callable
**********************************************************************
File "src/sage/rings/polynomial/skew_polynomial_ring.py", line 998, in
sage.rings.polynomial.skew_polynomial_ring.SkewPolynomialRing_general.centre
Failed example:
c = a + b; c
Exception raised:
Traceback (most recent call last):
File
"/home/arpit/Documents/GSOC_16/sage-7.2/local/lib/python2.7/site-packages/sage/doctest/forker.py",
line 496, in _run
self.compile_and_execute(example, compiler, test.globs)
File
"/home/arpit/Documents/GSOC_16/sage-7.2/local/lib/python2.7/site-packages/sage/doctest/forker.py",
line 858, in compile_and_execute
exec(compiled, globs)
File "<doctest
sage.rings.polynomial.skew_polynomial_ring.SkewPolynomialRing_general.centre[9]>",
line 1, in <module>
c = a + b; c
NameError: name 'a' is not defined
**********************************************************************
File "src/sage/rings/polynomial/skew_polynomial_ring.py", line 1000, in
sage.rings.polynomial.skew_polynomial_ring.SkewPolynomialRing_general.centre
Failed example:
c.parent()
Exception raised:
Traceback (most recent call last):
File
"/home/arpit/Documents/GSOC_16/sage-7.2/local/lib/python2.7/site-packages/sage/doctest/forker.py",
line 496, in _run
self.compile_and_execute(example, compiler, test.globs)
File
"/home/arpit/Documents/GSOC_16/sage-7.2/local/lib/python2.7/site-packages/sage/doctest/forker.py",
line 858, in compile_and_execute
exec(compiled, globs)
File "<doctest
sage.rings.polynomial.skew_polynomial_ring.SkewPolynomialRing_general.centre[10]>",
line 1, in <module>
c.parent()
NameError: name 'c' is not defined
**********************************************************************
2 items had failures:
3 of 18 in
sage.rings.polynomial.skew_polynomial_ring.SkewPolynomialRing_general.centre
1 of 12 in
sage.rings.polynomial.skew_polynomial_ring.SkewPolynomialRing_general.twist_map
[151 tests, 4 failures, 0.22 s]
----------------------------------------------------------------------
sage -t src/sage/rings/polynomial/skew_polynomial_ring.py # 4 doctests failed
----------------------------------------------------------------------
Total time for all tests: 0.3 seconds
cpu time: 0.2 seconds
cumulative wall time: 0.2 seconds
