Function: charpoly
Section: linear_algebra
C-Name: charpoly0
Prototype: GDnD0,L,
Help: charpoly(A,{v=x},{flag=0}): det(v*Id-A)=characteristic polynomial of
 the matrix or polmod A. flag is optional and may be set to 1 (use
 Lagrange interpolation) or 2 (use Hessenberg form), 0 being the default

