We describe algorithms and their implementations that calculate local and
global Schur indices of ordinary irreducible characters of finite groups and
cyclotomic algebras over abelian number fields. Side benefits include functions
for cyclotomic reciprocity calculations and for calculating the defect group
associated with an ordinary irreducible character of a finite group. These
functions are available in
GAP via the package
wedderga, versions 4.7 and
higher.
