On the Modification of LDII Factorizations
نویسندگان
چکیده
T Abstract. A number of methods are compared for modifying an LDL factorization of a positive definite matrix A when a matrix of rank one is added to A. Both the efficiency and error propagation characteristics are discussed, and it is shown that a suitable method must be chosen with care. An error analysis of some of the algorithms is given which has novel features. A worked example which also illustrates error growth is presented. Extensions to the methods are desribed which enable them to be used advantageously in representing and updating positive semidefinite matrices.
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تاریخ انتشار 2010