X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;ds=sidebyside;f=mjo%2Feja%2Feja_element_subalgebra.py;fp=mjo%2Feja%2Feja_element_subalgebra.py;h=0000000000000000000000000000000000000000;hb=e4d568e25c62d79a2dbe34b81ee4dc21edf09316;hp=34a63afdc0be38fb34ab95bb211df6d926d9be57;hpb=43b5bfdb82d46ed04f0f0ecaa1d34893453376b1;p=sage.d.git diff --git a/mjo/eja/eja_element_subalgebra.py b/mjo/eja/eja_element_subalgebra.py deleted file mode 100644 index 34a63af..0000000 --- a/mjo/eja/eja_element_subalgebra.py +++ /dev/null @@ -1,109 +0,0 @@ -from sage.matrix.constructor import matrix -from sage.misc.cachefunc import cached_method -from sage.rings.all import QQ - -from mjo.eja.eja_subalgebra import FiniteDimensionalEJASubalgebra - - -class FiniteDimensionalEJAElementSubalgebra(FiniteDimensionalEJASubalgebra): - def __init__(self, elt, **kwargs): - superalgebra = elt.parent() - - # TODO: going up to the superalgebra dimension here is - # overkill. We should append p vectors as rows to a matrix - # and continually rref() it until the rank stops going - # up. When n=10 but the dimension of the algebra is 1, that - # can save a shitload of time (especially over AA). - powers = tuple( elt**k for k in range(elt.degree()) ) - - super().__init__(superalgebra, - powers, - associative=True, - **kwargs) - - # The rank is the highest possible degree of a minimal - # polynomial, and is bounded above by the dimension. We know - # in this case that there's an element whose minimal - # polynomial has the same degree as the space's dimension - # (remember how we constructed the space?), so that must be - # its rank too. - self.rank.set_cache(self.dimension()) - - - @cached_method - def one(self): - """ - Return the multiplicative identity element of this algebra. - - The superclass method computes the identity element, which is - beyond overkill in this case: the superalgebra identity - restricted to this algebra is its identity. Note that we can't - count on the first basis element being the identity -- it might - have been scaled if we orthonormalized the basis. - - SETUP:: - - sage: from mjo.eja.eja_algebra import (HadamardEJA, - ....: random_eja) - - EXAMPLES:: - - sage: J = HadamardEJA(5) - sage: J.one() - e0 + e1 + e2 + e3 + e4 - sage: x = sum(J.gens()) - sage: A = x.subalgebra_generated_by(orthonormalize=False) - sage: A.one() - f0 - sage: A.one().superalgebra_element() - e0 + e1 + e2 + e3 + e4 - - TESTS: - - The identity element acts like the identity over the rationals:: - - sage: set_random_seed() - sage: x = random_eja(field=QQ,orthonormalize=False).random_element() - sage: A = x.subalgebra_generated_by() - sage: x = A.random_element() - sage: A.one()*x == x and x*A.one() == x - True - - The identity element acts like the identity over the algebraic - reals with an orthonormal basis:: - - sage: set_random_seed() - sage: x = random_eja().random_element() - sage: A = x.subalgebra_generated_by() - sage: x = A.random_element() - sage: A.one()*x == x and x*A.one() == x - True - - The matrix of the unit element's operator is the identity over - the rationals:: - - sage: set_random_seed() - sage: x = random_eja(field=QQ,orthonormalize=False).random_element() - sage: A = x.subalgebra_generated_by(orthonormalize=False) - sage: actual = A.one().operator().matrix() - sage: expected = matrix.identity(A.base_ring(), A.dimension()) - sage: actual == expected - True - - The matrix of the unit element's operator is the identity over - the algebraic reals with an orthonormal basis:: - - sage: set_random_seed() - sage: x = random_eja().random_element() - sage: A = x.subalgebra_generated_by() - sage: actual = A.one().operator().matrix() - sage: expected = matrix.identity(A.base_ring(), A.dimension()) - sage: actual == expected - True - - """ - if self.dimension() == 0: - return self.zero() - - return self(self.superalgebra().one()) -