[GAP Forum] some question about compute the order of centralizer

[Yang Liu]

Dear Forum,
  Let F be  a finite field of order p and V be a vector space over F  of dimension n. Choose a,b belong to GL(n,F) and G=<a,b>, the group generated by a and b. Then V may be viewed as an F[G]-module.
  For any element v of  V, how to compute the order of the centralizer of v in G ?
Best wishes,
Yang Liu.