---
title: "Magma V2.27-9 Patch Notes"
canonical: "https://docs.magma-maths.org/patchnotes/2.27-9.html"
source: "https://docs.magma-maths.org/patchnotes/2.27-9.md"
---

<a id="magma-v2-27-9-patch-notes"></a>
# Magma V2.27-9 Patch Notes

## Algebraic Number Fields

- `RelativeField(F, F)` now returns a linear extension of `F` as documented. Reported by J. Schleucher.

## Commutative Algebra

- A bug in `Kernel` for matrices defined over a field of fractions of an affine algebra has been fixed.  Reported by M. Cuntz.
- A crash in `PrimaryDecomposition` over rational function fields in higher characteristic (arising from computing divisors of points on schemes) has been fixed.  Reported by M. Houben.

## Galois Groups

- [`IsEasySnAn`](../GlobalFields/GaloisGroupsAndAutomorphisms/galois.md#function-iseasysnan-rngupolelt) has been fixed when the input polynomial has non trivial denominators. Reported by N. Katz.

## Lattices

- The function [`Orthonormalize`](../LatticesQuadraticForms/Lattices/ortho.md#function-orthonormalize-mtrxspcelt-fld) has been improved so that it is more stable and gives a correct informative error message if there are precision problems.  Issue reported by A. Budroni.

## Matrices

- A bug in [`FrobeniusFormAlternating`](../MatricesLinearAlgebra/Matrices/canonical.md#function-frobeniusformalternating-algmatelt) where the result did not satisfy the divisibility condition has been fixed. Reported by S. Hashimoto.

## Representation Theory

- A bug in `CompositionSeries` for a QG-module when its irreducibity attribute was already set has been fixed. Reported by J. Feuerpfeil.

## Sparse Matrices

- A crash in [`SetEntry`](../MatricesLinearAlgebra/SparseMatrices/entries.md#function-smat-setentry) when dynamically extending a sparse matrix while setting an entry to zero has been fixed.  Reported by H. Yau.

## Strings

- The versions of `Position` and `index` that take a starting offset have been moved into the kernel and are now substantially faster and more memory friendly.