Variable-step preconditioned conjugate gradient method for partial symmetric eigenvalue problems

摘要: in which A is a large sparse symmetric positive definite matrix, λ an eigenvalue and u corresponding eigenvector. The evaluation of one or more smallest eigenpairs has much practical interest for describing the characteristics physical phenomena. For example, eigenvalues characterize base frequences vibrating mechanical structures. Typically, matrix discretization arising as result finite-difference, finite element volume elliptic boundary value problems with self-adjoint differential operators on mesh characteristic meshsize h, n real