X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=mjo%2Feja%2Feja_algebra.py;h=f38128adf646c2dabcdd02cbfc26797731d472a2;hb=a7b393c90d9ad22641185e3b959ab17fc6e1e9d8;hp=afd0f55c103c885315e99bc90afe647262aadfbd;hpb=3844eed972d91ce88b1504818b37ee9428d95c68;p=sage.d.git diff --git a/mjo/eja/eja_algebra.py b/mjo/eja/eja_algebra.py index afd0f55..f38128a 100644 --- a/mjo/eja/eja_algebra.py +++ b/mjo/eja/eja_algebra.py @@ -1,4 +1,4 @@ -""" +r""" Representations and constructions for Euclidean Jordan algebras. A Euclidean Jordan algebra is a Jordan algebra that has some @@ -34,12 +34,13 @@ for these simple algebras: * :class:`QuaternionHermitianEJA` * :class:`OctonionHermitianEJA` -In addition to these, we provide two other example constructions, +In addition to these, we provide a few other example constructions, * :class:`JordanSpinEJA` * :class:`HadamardEJA` * :class:`AlbertEJA` * :class:`TrivialEJA` + * :class:`ComplexSkewSymmetricEJA` The Jordan spin algebra is a bilinear form algebra where the bilinear form is the identity. The Hadamard EJA is simply a Cartesian product @@ -1447,26 +1448,13 @@ class FiniteDimensionalEJA(CombinatorialFreeModule): # For a general base ring... maybe we can trust this to do the # right thing? Unlikely, but. V = self.vector_space() - v = V.random_element() - - if self.base_ring() is AA: - # The "random element" method of the algebraic reals is - # stupid at the moment, and only returns integers between - # -2 and 2, inclusive: - # - # https://trac.sagemath.org/ticket/30875 - # - # Instead, we implement our own "random vector" method, - # and then coerce that into the algebra. We use the vector - # space degree here instead of the dimension because a - # subalgebra could (for example) be spanned by only two - # vectors, each with five coordinates. We need to - # generate all five coordinates. - if thorough: - v *= QQbar.random_element().real() - else: - v *= QQ.random_element() + if self.base_ring() is AA and not thorough: + # Now that AA generates actually random random elements + # (post Trac 30875), we only need to de-thorough the + # randomness when asked to. + V = V.change_ring(QQ) + v = V.random_element() return self.from_vector(V.coordinate_vector(v)) def random_elements(self, count, thorough=False): @@ -1812,14 +1800,13 @@ class RationalBasisEJA(FiniteDimensionalEJA): # Bypass the hijinks if they won't benefit us. return super()._charpoly_coefficients() - # Do the computation over the rationals. The answer will be - # the same, because all we've done is a change of basis. - # Then, change back from QQ to our real base ring + # Do the computation over the rationals. a = ( a_i.change_ring(self.base_ring()) for a_i in self.rational_algebra()._charpoly_coefficients() ) - # Otherwise, convert the coordinate variables back to the - # deorthonormalized ones. + # Convert our coordinate variables into deorthonormalized ones + # and substitute them into the deorthonormalized charpoly + # coefficients. R = self.coordinate_polynomial_ring() from sage.modules.free_module_element import vector X = vector(R, R.gens())