---
title: "Magma V2.22-4 Patch Notes"
canonical: "https://docs.magma-maths.org/patchnotes/2.22-4.html"
source: "https://docs.magma-maths.org/patchnotes/2.22-4.md"
---

<a id="magma-v2-22-4-patch-notes"></a>
# Magma V2.22-4 Patch Notes

## Algebraic Function Fields

- The algorithm choice for computing a 2-element representation of an ideal has been improved. Reported by R. Granger.

## Coding Theory

- The function `ExtendCode` has been restored (accidentally only available as `ExtendCodeField` previously).  Issue reported by D.W.C. Kuijsters.

## Commutative Algebra

- Some operations with of fields of fractions of affine algebras have been sped up.  Related crash (now fixed) reported by T. Ikuta.
- A bug in factoring polynomials over polynomial quotient rings over finite fields (which are themselves finite fields) has been fixed. Reported by A. Sutherland.
- A problem with linear factors in reducible polynomials has been fixed. Reported by A-S. Elsenhans.
- Crashes in Groebner basis computation over the rational field has been fixed.  Reported by A-S. Elsenhans.

## Cubic models of curves

- A crash with [`PointSearch`](../AlgebraicGeometry/Schemes/anfs.md#function-pointsearch-sch-fldrat-rngintelt) for cubic models has been fixed.

## Dedekind Modules

- A crash involving Dedekind modules has been fixed. Reported by V. Kliuchnikov.
- A crash when constructing a Dedekind module of degree 0 has been fixed. Reported by M. Kirschmer.

## Finite Fields

- A crash when trying to compute a logarithm in a large finite field for which the data is not available has been fixed. Reported by M. Tillinghast.

## Graphs

- Using `'in'` to test whether a set or sequence of vertices is in the edge set of a graph now returns false instead of raising an error when there is no corresponding edge.

## Group Characters

- A crash in the group characters code has been fixed. Bug report from Matthieu Rambaud.
- The intrinsic `Basis` when applied to a character ring now uses the default `CharacterTable` algorithm, instead of always going to the Dixon-Schneider algorithm.

## Groups

- Calls to the [`ASp`](../FiniteGroups/PermutationGroups/linear-group.md#literal-literal-asp-asp-arguments) functions now trap odd dimensions to give a runtime error. Bug reported by T. Dokchitser.
- A crash when computing projective classical groups over a large finite field has been fixed. Bug reported by T. Dokchitser.
- Incorrect construction of some low dimensional [`PGO`](../FiniteGroups/PermutationGroups/linear-group.md#literal-literal-pgo-pgo-arguments) groups fixed. Bug reported by T. Dokchitser.
- Dimension lower bounds on the [`Spin`](../FiniteGroups/AlmostSimpleGroups/standard.md#function-spin-rngintelt-rngintelt), [`SpinPlus`](../FiniteGroups/AlmostSimpleGroups/standard.md#function-spinplus-rngintelt-rngintelt) and [`SpinMinus`](../FiniteGroups/AlmostSimpleGroups/standard.md#function-spinminus-rngintelt-rngintelt) intrinsics are all now 4. This fixes a crash reported by T. Dokchitser.
- The order assigned to [`PSigmaU(2,q)`](../FiniteGroups/PermutationGroups/linear-group.md#literal-literal-psigmau-psigmau-arguments), when q = 3 mod 4, has been corrected. Bug reported by T. Dokchitser.
- An improved access function for a single [`SmallGroup`](../FiniteGroups/DatabasesOfGroups/smlgps-database.md#function-grpdata-smallgroup) of order p^7 (p >= 7) is included. Request of E. O’Brien.

## Hyperelliptic curves

- A longstanding bug with point counts on genus 1 hyperelliptic curves has been fixed (the twisting parameter was applied twice). Reported by E. Howe.

## Lattices

- A crash with [`BKZ`](../LatticesQuadraticForms/Lattices/reduction.md#function-bkz-mtrx-rngintelt) when the number of columns exceeded the rank was fixed. Reported by A.-S. Elsenhans.

## Matrix Algebras

- A bug involving the wrong element type when iterating over a matrix lie algebra has been fixed.  Reported by J. Maglione.

## Numerical Linear Algebra

- A problem with images of complex matrices was fixed.

## Sparse Matrices

- A missing error check has been added to `Nullspace` applied to sparse matrices over rings which are not supported. Reported by D. Yasaki.