Sage 10.10 Release Tour

These are the work-in-progress release notes for the 10.10 release. Contributions are welcome!

For the current stable version, see the Sage 10.9 Release Tour.

Combinatorics

Growth Diagrams and Dual Graded Graphs

Growth diagrams now have a dedicated LaTeX method, which supports arbitrary edge and vertex labels. Moreover, the testsuite now checks that the implemented forward and backward rules respect the basic invariants, which makes it even easier to add new growth diagrams. Finally, the growth diagrams due to Stephanie van Willigenburg, Dual graphs from noncommutative and quasisymmetric Schur functions, have been added to the library. #41764, #42079

Matroids

The method is_quaternary is now available. A matroid is quaternary (i.e., $\text{GF}(4)$-representable) if and only if it has no minor isomorphic to any of the matroids $U_{2, 6}$, $U_{4, 6}$, $P_6$, $F_7^-$, $(F_7^-)^*$, $P_8$, and $P_8^=$. #42305

Multi-polynomial ideals

We have extended support to the integers by integrating the following functions from Singular's primdecint.lib #42386:

 primdecZ(I);       compute the primary decomposition of ideal I
 minAssZ(I);        compute the minimal associated primes of I
 radicalZ(I);       compute the radical of I
 heightZ(I);        compute the height of I
 equidimZ(I);       compute the equidimensional part of I
 intersectZ(I,J)    compute the intersection of I and J

Usage example:

sage: R.<x, y> = PolynomialRing(ZZ, 2)
sage: I = R.ideal(x^2 + 1, y^2 + 1)
sage: I.minimal_associated_primes()
[Ideal (x - y, y^2 + 1) of Multivariate Polynomial Ring in x, y over Integer Ring,
 Ideal (x + y, y^2 + 1) of Multivariate Polynomial Ring in x, y over Integer Ring]

This used to yield a ValueError: Coefficient ring must be a field for function 'minimal_associated_primes'.

Old Parents

In 2008, Parent in parent_old.py, ParentWithGens and ParentWithBase were deprecated. With this release, they are gone!