
slaed5.f(3) LAPACK slaed5.f(3)
NAME
slaed5.f 
SYNOPSIS
Functions/Subroutines
subroutine slaed5 (I, D, Z, DELTA, RHO, DLAM)
SLAED5 used by sstedc. Solves the 2by2 secular equation.
Function/Subroutine Documentation
subroutine slaed5 (integerI, real, dimension( 2 )D, real, dimension( 2 )Z, real, dimension( 2
)DELTA, realRHO, realDLAM)
SLAED5 used by sstedc. Solves the 2by2 secular equation.
Purpose:
This subroutine computes the Ith eigenvalue of a symmetric rankone
modification of a 2by2 diagonal matrix
diag( D ) + RHO * Z * transpose(Z) .
The diagonal elements in the array D are assumed to satisfy
D(i) < D(j) for i < j .
We also assume RHO > 0 and that the Euclidean norm of the vector
Z is one.
Parameters:
I
I is INTEGER
The index of the eigenvalue to be computed. I = 1 or I = 2.
D
D is REAL array, dimension (2)
The original eigenvalues. We assume D(1) < D(2).
Z
Z is REAL array, dimension (2)
The components of the updating vector.
DELTA
DELTA is REAL array, dimension (2)
The vector DELTA contains the information necessary
to construct the eigenvectors.
RHO
RHO is REAL
The scalar in the symmetric updating formula.
DLAM
DLAM is REAL
The computed lambda_I, the Ith updated eigenvalue.
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
September 2012
Contributors:
RenCang Li, Computer Science Division, University of California at Berkeley, USA
Definition at line 109 of file slaed5.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Tue Sep 25 2012 slaed5.f(3) 
