Function: bnrgaloismatrix
Section: number_fields
C-Name: bnrgaloismatrix
Prototype: GG
Help: bnrgaloismatrix(bnr,aut): return the matrix of the action of the
 automorphism aut of the base field bnf.nf on the generators of the ray class
 field bnr.gen. aut can be given as a polynomial, or a vector of automorphisms
 or a galois group as output by galoisinit, in which case a vector of matrices
 is returned (in the later case, only for the generators aut.gen).
Doc: return the matrix of the action of the automorphism \var{aut} of the base
 field \kbd{bnf.nf} on the generators of the ray class field \kbd{bnr.gen}.
 \var{aut} can be given as a polynomial, an algebraic number, or a vector of
 automorphisms or a Galois group as output by \kbd{galoisinit}, in which case a
 vector of matrices is returned (in the later case, only for the generators
 \kbd{aut.gen}).

 See \kbd{bnrisgalois} for an example.
Variant: When $aut$ is a polynomial or an algebraic number,
 \fun{GEN}{bnrautmatrix}{GEN bnr, GEN aut} is available.
