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SSTERF(1) LAPACK routine (version 3.2) SSTERF(1)

NAME

SSTERF - computes all eigenvalues of a symmetric tridiagonal matrix using the Pal-Walker-Kahan variant of the QL or QR algorithm

SYNOPSIS

N, D, E, INFO )

INTEGER INFO, N REAL D( * ), E( * )

PURPOSE

SSTERF computes all eigenvalues of a symmetric tridiagonal matrix using the Pal-Walker-Kahan variant of the QL or QR algorithm.

ARGUMENTS

The order of the matrix. N >= 0.
On entry, the n diagonal elements of the tridiagonal matrix. On exit, if INFO = 0, the eigenvalues in ascending order.
On entry, the (n-1) subdiagonal elements of the tridiagonal matrix. On exit, E has been destroyed.
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
> 0: the algorithm failed to find all of the eigenvalues in a total of 30*N iterations; if INFO = i, then i elements of E have not converged to zero.
November 2008 LAPACK routine (version 3.2)