Some quick data points: - The general graded modules (and hence algebras) code raises an error for `0` since it is defined there by the direct summand the element belongs to (and `0` belongs to all of them. - For polynomials, it is very useful to have a single check `f.degree() > k` for some `k`. Having error messages or check `f.is_zero()` first makes things more complicated. - Comparisons of integers to `-infinity` is (relatively) expensive. Although this happening frequently seems unlikely.
Martin, note that Dima is calling degree with a min/max qualifier added in front. I think this is leading to some confusion and cross-talk. However, I think it is better to have easily separable terms "valuation" and "degree" (which exist for polynomials). Best, Travis On Saturday, March 2, 2024 at 3:44:55 AM UTC+9 Martin R wrote: > I don't get it - are my previous messages invisible? > > 1st Message: I don't understand - `degree` doesn't make much sense for > Laurent series - there is no way to determine the degree of a LaurentSeries > and no way to determine the degree of a LazyLaurentSeries with one minor > exception - which is when it is known that the series terminates, but > that's rare. > > 2nd Message: I am very much against this. I realise that this is a > convention one uses in mathematics, but here it would be extremely > confusing: in the lazy series code we use valuation a lot, and it must mean > lowest degree, but we also use the degree of polynomials and Laurent > polynomials and we must distinguish between the two. > > I feel a bit ignored, > > Martin > > > On Friday 1 March 2024 at 19:29:26 UTC+1 Giacomo Pope wrote: > > As an aside, the univariate LaurentPolynomialRing had a notion of > `valuation` but the multivariate one didn't... > > In the PR: https://github.com/sagemath/sage/pull/37490 I added random > elements but also a notion of valuation() for the multivariate case and > just made it act similarly to the univariate one. > > On Friday, March 1, 2024 at 6:18:01 PM UTC Nils Bruin wrote: > > On Friday 1 March 2024 at 09:49:15 UTC-8 Giacomo Pope wrote: > > Following this discussion, I have made a draft PR to change the degree for > *only* the LaurentPolynomialRing and I will see if the CI detects anything. > > https://github.com/sagemath/sage/pull/37513 > > I agree that if we change the LaurentPolynomialRing we should also change > the `LaurentSeriesRing`, at the moment `LazyLaurentSeriesRing` has no > method `degree()` but *does* have a `valuation()` method... so this is odd. > > > OK, let's keep it that way then! I don't think there is a notion on > LaurentSeriesRing that deserves the name "degree". Sorry about mixing that > one in. I thought it existed. And I think it does: > > sage: R.<x>=LaurentSeriesRing(QQ) > sage: z=R(0) > sage: z.valuation() > +Infinity > sage: z.degree() > -1 > > but if it's not documented, perhaps we can just ignore it. > > -- 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/6a9a6131-8c51-4760-9fad-897e220bfd1fn%40googlegroups.com.
