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.