While chasing various bugs which appeared in the CI, I ended up adding a small method for computing random elements for the LaurentPolynomialRing class.
When writing randomised testing I got myself confused about the degree of the zero polynomial. For the univariate and multivariate polynomial rings, we currently use that the degree for 0 (both R(0).degree() as well as R(0).degree(x)) is -1. This is unambiguous for the case of these types. However for the LaurentPolynomialRings, a polynomial with negative valuation is very natural. For example the following code snippet shows the ambiguity. sage: L.<x> = LaurentPolynomialRing(QQ) sage: f = (1/x); f x^-1 sage: f.degree() -1 sage: L.zero().degree() -1 I don't feel familiar enough with the mathematics here and the usual use cases in sage to offer a PR "fixing" this, or whether it even needs fixing. However, I got confused so I thought maybe others might get confused and someone on this list might have a suggestion. I think the "usual" suggestion would be to have the degree as -infty, but then there's a question about whether this should be done for other polynomial rings... I made an issue for this on GitHub too: https://github.com/sagemath/sage/issues/37491 -- 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 sage-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/0efa0dd8-b322-4896-b9af-a88effeaa195n%40googlegroups.com.
