A structure-preserving iteration method of model updating based on matrix approximation theory

some theories and a method are discussed on updating a generalized centrosymmetric model. it gives a generalized centrosymmetric modified solution with partial prescribed least square spectra constraints. the emphasis is given on exploiting structure-preserving algorithm based on matrix approximation theory. a perturbation theory for the modified solution is established. the convergence of an iterative solution is investigated. illustrative examples are provided. mathematical subject classification: 15a29, 15a90, 41a29, 65f15, 65l70.