  We propose a contour integral-based algorithm for computing a few singular
values of a matrix or a few generalized singular values of a matrix pencil.
Mathematically, the generalized singular values of a matrix pencil are the
eigenvalues of an equivalent Hermitian-definite matrix pencil, known as the
Jordan-Wielandt matrix pencil. However, direct application of the FEAST solver
does not fully exploit the structure of this problem. We analyze several
projection strategies on the Jordan-Wielandt matrix pencil, and propose an
effective and robust scheme tailored to GSVD. Both theoretical analysis and
numerical experiments demonstrate that our algorithm achieves rapid convergence
and satisfactory accuracy.
