This is a variable name clash. Somehow, using 'x' for modulus creates a problem. If I instead do
T.<xx>=GF(2)[] K.<a>=GF(2^6, modulus=xx^6 + xx^4 + xx^3 + xx + 1) ... then everything works as expected. On Fri, Nov 22, 2019 at 9:51 AM Dima Pasechnik <dimp...@gmail.com> wrote: > > This is now https://trac.sagemath.org/ticket/28786 > Note that it only happens if modulus is explicitly given. > > On Fri, Nov 22, 2019 at 9:47 AM Dima Pasechnik <dimp...@gmail.com> wrote: > > > > yes, I can confirm this is still giving an error in the latest Sage > > beta. (9.0.beta6). > > Note that actually it's two identical inputs, the 2nd executed after > > the 1st gives the error. > > > > I'll open a ticket. > > > > On Fri, Nov 22, 2019 at 7:53 AM Samanta <susantasamant...@gmail.com> wrote: > > > > > > I did not understand why the error has occurred. For the first time, it > > > returned output but for the second time when I run the same code, I found > > > an error "ValueError: the degree of the modulus does not equal the degree > > > of the field" which is also not true as my irreducible polynomial has > > > degree 6. > > > I am attaching my code and output for two consecutive times. > > > > > > sage: K.<a>=GF(2^6, modulus=x^6 + x^4 + x^3 + x + 1) > > > ....: x=a^9 > > > ....: y=a^21 > > > ....: z=1/x > > > ....: v=vector([1,y,y^2,y^3,y^4,y^5,y^6]) > > > ....: > > > S=matrix([[1,1,1,1,1,1,1],[1,z,z^2,z^3,z^4,z^5,z^6],[1,(z^2),(z^2)^2,(z^2)^3,(z^2)^4,(z^2)^5,(z^2)^6],[1,(z^3),(z^3)^2,(z^3)^3,(z^3)^4,(z^ > > > ....: > > > 3)^5,(z^3)^6],[1,(z^4),(z^4)^2,(z^4)^3,(z^4)^4,(z^4)^5,(z^4)^6],[1,(z^5),(z^5)^2,(z^5)^3,(z^5)^4,(z^5)^5,(z^5)^6],[1,(z^6),(z^6)^2,(z^6)^3 > > > ....: ,(z^6)^4,(z^6)^5,(z^6)^6]]) > > > ....: w=S*v > > > ....: w > > > ....: > > > (1, a^3 + a + 1, a^5 + a^4 + a^3 + a^2 + 1, a^4 + a^3 + a^2, a^5 + a^4 + > > > a^3, a^3 + a^2 + 1, a^4 + a^3 + a^2 + a + 1) > > > > > > sage: K.<a>=GF(2^6, modulus=x^6 + x^4 + x^3 + x + 1) > > > ....: x=a^9 > > > ....: y=a^21 > > > ....: z=1/x > > > ....: v=vector([1,y,y^2,y^3,y^4,y^5,y^6]) > > > ....: > > > S=matrix([[1,1,1,1,1,1,1],[1,z,z^2,z^3,z^4,z^5,z^6],[1,(z^2),(z^2)^2,(z^2)^3,(z^2)^4,(z^2)^5,(z^2)^6],[1,(z^3),(z^3)^2,(z^3)^3,(z^3)^4,(z^ > > > ....: > > > 3)^5,(z^3)^6],[1,(z^4),(z^4)^2,(z^4)^3,(z^4)^4,(z^4)^5,(z^4)^6],[1,(z^5),(z^5)^2,(z^5)^3,(z^5)^4,(z^5)^5,(z^5)^6],[1,(z^6),(z^6)^2,(z^6)^3 > > > ....: ,(z^6)^4,(z^6)^5,(z^6)^6]]) > > > ....: w=S*v > > > ....: w > > > ....: > > > --------------------------------------------------------------------------- > > > ValueError Traceback (most recent call > > > last) > > > <ipython-input-3-37bf7e6f8848> in <module>() > > > ----> 1 K = GF(Integer(2)**Integer(6), modulus=x**Integer(6) + > > > x**Integer(4) + x**Integer(3) + x + Integer(1), names=('a',)); (a,) = > > > K._first_ngens(1) > > > 2 x=a**Integer(9) > > > 3 y=a**Integer(21) > > > 4 z=Integer(1)/x > > > 5 > > > v=vector([Integer(1),y,y**Integer(2),y**Integer(3),y**Integer(4),y**Integer(5),y**Integer(6)]) > > > > > > /home/susanta/Desktop/SageMath/local/lib/python2.7/site-packages/sage/structure/factory.pyx > > > in sage.structure.factory.UniqueFactory.__call__ > > > (build/cythonized/sage/structure/factory.c:2162)() > > > 366 False > > > 367 """ > > > --> 368 key, kwds = self.create_key_and_extra_args(*args, **kwds) > > > 369 version = self.get_version(sage_version) > > > 370 return self.get_object(version, key, kwds) > > > > > > /home/susanta/Desktop/SageMath/local/lib/python2.7/site-packages/sage/rings/finite_rings/finite_field_constructor.pyc > > > in create_key_and_extra_args(self, order, name, modulus, names, impl, > > > proof, check_irreducible, prefix, repr, elem_cache, **kwds) > > > 583 > > > 584 if modulus.degree() != n: > > > --> 585 raise ValueError("the degree of the > > > modulus does not equal the degree of the field") > > > 586 if check_irreducible and not > > > modulus.is_irreducible(): > > > 587 raise ValueError("finite field modulus > > > must be irreducible but it is not") > > > > > > ValueError: the degree of the modulus does not equal the degree of the > > > field > > > > > > -- > > > You received this message because you are subscribed to the Google Groups > > > "sage-support" group. > > > To unsubscribe from this group and stop receiving emails from it, send an > > > email to sage-support+unsubscr...@googlegroups.com. > > > To view this discussion on the web visit > > > https://groups.google.com/d/msgid/sage-support/47e0cba1-d1be-40b7-b376-cfa537b68e29%40googlegroups.com. -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/CAAWYfq167j%3DVciCDWp1z9_ws%2Bqgse4aF1AUWdbeu27G6PJc3ag%40mail.gmail.com.
