Man page - sterf(3)

Packages contains this manual

Manual

sterf

NAME
SYNOPSIS
Functions
Detailed Description
Function Documentation
subroutine dsterf (integer n, double precision, dimension( * ) d, doubleprecision, dimension( * ) e, integer info)
subroutine ssterf (integer n, real, dimension( * ) d, real, dimension( * )e, integer info)
Author

NAME

sterf - sterf: eig, QR iteration

SYNOPSIS

Functions

subroutine dsterf (n, d, e, info)
DSTERF
subroutine ssterf (n, d, e, info)
SSTERF

Detailed Description

Function Documentation

subroutine dsterf (integer n, double precision, dimension( * ) d, doubleprecision, dimension( * ) e, integer info)

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.

subroutine ssterf (integer n, real, dimension( * ) d, real, dimension( * )e, integer info)

SSTERF

Purpose:

SSTERF 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 REAL 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 REAL 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.

Author

Generated automatically by Doxygen for LAPACK from the source code.