X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=mjo%2Foctonions.py;h=87bf5ff1ed06b1a77b5815df8dd2248fda4b7edb;hb=9ffb2ed473d62df9f6b6db9636b0bf8fa8f3be25;hp=352c4c586e7506a218bcc9e7f9cb6332c1cd72c7;hpb=ee21aa47a00c19068c21d631fda6598a6e0648e9;p=sage.d.git diff --git a/mjo/octonions.py b/mjo/octonions.py index 352c4c5..87bf5ff 100644 --- a/mjo/octonions.py +++ b/mjo/octonions.py @@ -445,6 +445,41 @@ class OctonionMatrix(IndexedFreeModuleElement): zero = self.parent().octonions().zero() return sum( (self[i,i] for i in range(self.nrows())), zero ) + def matrix_space(self): + r""" + + SETUP:: + + sage: from mjo.octonions import OctonionMatrixAlgebra + + TESTS:: + + sage: set_random_seed() + sage: MS = OctonionMatrixAlgebra(2) + sage: MS.random_element().matrix_space() + Module of 2 by 2 matrices with octonion entries over the + scalar ring Algebraic Real Field + + """ + return self.parent() + + def is_hermitian(self): + r""" + + SETUP:: + + sage: from mjo.octonions import OctonionMatrixAlgebra + + EXAMPLES:: + + sage: MS = OctonionMatrixAlgebra(3) + sage: MS.one().is_hermitian() + True + + """ + return all( self[i,j] == self[j,i].conjugate() + for i in range(self.nrows()) + for j in range(self.ncols()) ) class OctonionMatrixAlgebra(CombinatorialFreeModule): r""" @@ -483,6 +518,11 @@ class OctonionMatrixAlgebra(CombinatorialFreeModule): prefix=prefix, bracket='(') + def _repr_(self): + return ("Module of %d by %d matrices with octonion entries" + " over the scalar ring %s" % + (self.nrows(), self.ncols(), self.base_ring()) ) + def octonions(self): r""" Return the Octonion algebra that our elements' entries come from.