On Monday, July 22, 2013 6:58:11 AM UTC-7, Volker Braun wrote: > > On Sunday, July 21, 2013 8:35:24 PM UTC-4, davidp wrote: > > At the moment, I just have Hyperplane as a class deriving from > AffineSpace (my version of AffineSpace, that is, which I will change, as > > noted above), and HyperplaneArrangement deriving from object. Can you > spell out your idea a bit more? > > All the data that define the ambient space, the base ring, etc goes into > the Parent. The element refers to the parent for constant data. Or, by > analogy: > > Element : Parent > Polynomial : PolynomialRing > Hyperplane : HyperplaneArrangement > > There isn't really a simple introduction, but > http://www.sagemath.org/doc/thematic_tutorials/coercion_and_categories.htmlspells > out all the details. > > I don't really see a need for another affine space. It would be very > confusing to present the user with multiple affine space implementations. >
I need a class to model an affine subspace of K^n where K is a finite field or QQ. An affine subspace has the form p + W where p is a point and W is a linear subspace of K^n. Besides testing for equality and containment, one main method I need is intersection: the output of intersect(self, other) is another affine space. Another useful method provides an isomorphism of an affine space of dimension d in K^n with K^d, and in the case K = QQ, one that is approximately orthogonal. Thus, AffineSpace does not really help. So maybe the problem is finding a better name for what I have in mind. Perhaps "AffineSubspace"? Or can you suggest a better idea? Thanks for your help! -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/groups/opt_out.
