Patch Notes

Magma V2.21-2 Patch Notes

Patch release for Magma V2.21-2. Updated areas: Coding Theory, Commutative Algebra, Groups, Multivariate Polynomials, Number Fields and 4 more.

9 areas

Coding Theory

  • ConstaCyclicCode is more efficient now, particularly for long codes where the constant has large order. Reported (and fixed) by M. Grassl.

Commutative Algebra

Groups

  • The new Group intrinsic did not operate correctly when given strings with "SU" involved. Similarly, "U" has been included as a synonym for "PSU".

Multivariate Polynomials

Number Fields

  • A problem with HeckeCharacterGroup of an abelian extension was fixed, taking into account infinite places.
  • The Extend intrinsics for Dirichlet and Hecke characters (and groups) have been modified to eliminate the extraneous second return value (there is not really a kernel involved). The Extend intrinsic for groups thus now returns a group of the same size.
  • The application of an automorphism to a fractional ideal of an order of a quadratic field has been fixed. Reported by M. Kirschmer.
  • The error checking in LLL and LLLBasisMatrix when the input is an ideal of an order of a number field has been improved to give a runtime error when the number field is not a direct extension of the rational field.
  • A problem with MinimalPolynomial was fixed, when the polynomial that was found had degree 0 (and thus trivial factorisation).

Schemes

  • Projective points with coordinates in Euclidean domains are now more strictly checked and as a result some points which have previously been able to be constructed are no longer able to be constructed.

System

  • Using sequence indexing on large strings (greater than 2GB) now works properly.
  • Read has been slightly sped up for larger files.
  • Some unnecessary memory duplication when calling eval has been removed.

Topology

  • Printing of objects of type SmpCpx has been fixed. Reported by K. Joanidis.

Vector Spaces

  • An incorrect answer has been fixed for the function ExtendBasis. Reported by R. Zeier.