dsterf.f man page

dsterf.f —

Synopsis

Functions/Subroutines

subroutine dsterf (N, D, E, INFO)
DSTERF

Function/Subroutine Documentation

subroutine dsterf (integerN, double precision, dimension( * )D, double precision, dimension( * )E, integerINFO)

DSTERF

Purpose:

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

Parameters:

N

N is INTEGER
The order of the matrix.  N >= 0.

D

D is DOUBLE PRECISION array, dimension (N)
On entry, the n diagonal elements of the tridiagonal matrix.
On exit, if INFO = 0, the eigenvalues in ascending order.

E

E is DOUBLE PRECISION array, dimension (N-1)
On entry, the (n-1) subdiagonal elements of the tridiagonal
matrix.
On exit, E has been destroyed.

INFO

INFO is INTEGER
= 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.

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

November 2011

Definition at line 87 of file dsterf.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

dsterf(3) is an alias of dsterf.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK