SLAED5(3F)							    SLAED5(3F)

NAME    [Toc]    [Back]

     SLAED5 - subroutine computes the I-th eigenvalue of a symmetric rank-one
     modification of a 2-by-2 diagonal matrix	diag( D	) + RHO	 The diagonal
     elements in the array D are assumed to satisfy   D(i) < D(j) for i	< j

SYNOPSIS    [Toc]    [Back]

     SUBROUTINE	SLAED5(	I, D, Z, DELTA,	RHO, DLAM )

	 INTEGER	I

	 REAL		DLAM, RHO

	 REAL		D( 2 ),	DELTA( 2 ), Z( 2 )

PURPOSE    [Toc]    [Back]

     This subroutine computes the I-th eigenvalue of a symmetric rank-one
     modification of a 2-by-2 diagonal matrix

     We	also assume RHO	> 0 and	that the Euclidean norm	of the vector Z	is
     one.

ARGUMENTS    [Toc]    [Back]

     I	    (input) INTEGER
	    The	index of the eigenvalue	to be computed.	 I = 1 or I = 2.

     D	    (input) REAL array,	dimension (2)
	    The	original eigenvalues.  We assume D(1) <	D(2).

     Z	    (input) REAL array,	dimension (2)
	    The	components of the updating vector.

     DELTA  (output) REAL array, dimension (2)
	    The	vector DELTA contains the information necessary	to construct
	    the	eigenvectors.

     RHO    (input) REAL
	    The	scalar in the symmetric	updating formula.

     DLAM   (output) REAL
	    The	computed lambda_I, the I-th updated eigenvalue.
SLAED5(3F)							    SLAED5(3F)

NAME    [Toc]    [Back]

     SLAED5 - subroutine computes the I-th eigenvalue of a symmetric rank-one
     modification of a 2-by-2 diagonal matrix	diag( D	) + RHO	 The diagonal
     elements in the array D are assumed to satisfy   D(i) < D(j) for i	< j

SYNOPSIS    [Toc]    [Back]

     SUBROUTINE	SLAED5(	I, D, Z, DELTA,	RHO, DLAM )

	 INTEGER	I

	 REAL		DLAM, RHO

	 REAL		D( 2 ),	DELTA( 2 ), Z( 2 )

PURPOSE    [Toc]    [Back]

     This subroutine computes the I-th eigenvalue of a symmetric rank-one
     modification of a 2-by-2 diagonal matrix

     We	also assume RHO	> 0 and	that the Euclidean norm	of the vector Z	is
     one.

ARGUMENTS    [Toc]    [Back]

     I	    (input) INTEGER
	    The	index of the eigenvalue	to be computed.	 I = 1 or I = 2.

     D	    (input) REAL array,	dimension (2)
	    The	original eigenvalues.  We assume D(1) <	D(2).

     Z	    (input) REAL array,	dimension (2)
	    The	components of the updating vector.

     DELTA  (output) REAL array, dimension (2)
	    The	vector DELTA contains the information necessary	to construct
	    the	eigenvectors.

     RHO    (input) REAL
	    The	scalar in the symmetric	updating formula.

     DLAM   (output) REAL
	    The	computed lambda_I, the I-th updated eigenvalue.


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