ELMHES(3F)
elmhes, selmhes - EISPACK routine. Given a REAL GENERAL matrix, this subroutine reduces a submatrix situated in rows and columns LOW through IGH to upper Hessenberg form by stabilized elementary similarity transformations.
As shipped in IRIX 6.5.7. Unchanged since IRIX 6.5.
NAME elmhes, selmhes - EISPACK routine. Given a REAL GENERAL matrix, this subroutine reduces a submatrix situated in rows and columns LOW through IGH to upper Hessenberg form by stabilized elementary similarity transformations. SYNOPSYS subroutine elmhes(nm, n, low, igh, a, int) integer nm, n, low, igh, int(igh) double precision a(nm,n) subroutine selmhes(nm, n, low, igh, a, int) integer nm, n, low, igh, int(igh) real a(nm,n) DESCRIPTION On INPUT NM must be set to the row dimension of two-dimensional array parameters as declared in the calling program dimension statement. N is the order of the matrix. LOW and IGH are integers determined by the balancing subroutine BALANC. If BALANC has not been used, set LOW=1, IGH=N. A contains the input matrix. On OUTPUT A contains the Hessenberg matrix. The multipliers which were used in the reduction are stored in the remaining triangle under the Hessenberg matrix. INT contains information on the rows and columns interchanged in the reduction. Only elements LOW through IGH are used. Questions and comments should be directed to B. S. Garbow, APPLIED MATHEMATICS DIVISION, ARGONNE NATIONAL LABORATORY