A FORTRAN 4Program for the Inversion of a Large Symmetric Matrix by Block Partitioning,

摘要

A computer program to invert a large symmetric matrix is described in the report. The given upper triangular portion of a symmetric matrix is partitioned and inverse returned as a result. The minimum region required by the program is 252 K bytes which is still enough to invert a 10000 x 10000symmetric matrix. If the matrix is not positive definite, a special bordering method (DBINV) is used to invert needed submatrices,otherwise a factorization method (DSINV) is used. The program requires two tape units,one for the input matrix,the other one for the resulting inverse. Four temporary direct access disk units are also needed. The program has been implemented on a IBM 370/165computer with a maximum user available core of 630 K bytes,not all of which may be needed by the programs described in this report. (Author)