.TH "dlaed5.f" 3 "Wed Oct 15 2014" "Version 3.4.2" "LAPACK" \" -*- nroff -*-
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.SH NAME
dlaed5.f \- 
.SH SYNOPSIS
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.SS "Functions/Subroutines"

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.RI "subroutine \fBdlaed5\fP (I, D, Z, DELTA, RHO, DLAM)"
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.RI "\fI\fBDLAED5\fP used by sstedc\&. Solves the 2-by-2 secular equation\&. \fP"
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.SH "Function/Subroutine Documentation"
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.SS "subroutine dlaed5 (integerI, double precision, dimension( 2 )D, double precision, dimension( 2 )Z, double precision, dimension( 2 )DELTA, double precisionRHO, double precisionDLAM)"

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\fBDLAED5\fP used by sstedc\&. Solves the 2-by-2 secular equation\&.  
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\fBPurpose: \fP
.RS 4

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.nf
 This subroutine computes the I-th eigenvalue of a symmetric rank-one
 modification of a 2-by-2 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.
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.RE
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\fBParameters:\fP
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\fII\fP 
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          I is INTEGER
         The index of the eigenvalue to be computed.  I = 1 or I = 2.
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\fID\fP 
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          D is DOUBLE PRECISION array, dimension (2)
         The original eigenvalues.  We assume D(1) < D(2).
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\fIZ\fP 
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          Z is DOUBLE PRECISION array, dimension (2)
         The components of the updating vector.
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\fIDELTA\fP 
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          DELTA is DOUBLE PRECISION array, dimension (2)
         The vector DELTA contains the information necessary
         to construct the eigenvectors.
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\fIRHO\fP 
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          RHO is DOUBLE PRECISION
         The scalar in the symmetric updating formula.
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\fIDLAM\fP 
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          DLAM is DOUBLE PRECISION
         The computed lambda_I, the I-th updated eigenvalue.
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.RE
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\fBAuthor:\fP
.RS 4
Univ\&. of Tennessee 
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Univ\&. of California Berkeley 
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Univ\&. of Colorado Denver 
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NAG Ltd\&. 
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\fBDate:\fP
.RS 4
September 2012 
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\fBContributors: \fP
.RS 4
Ren-Cang Li, Computer Science Division, University of California at Berkeley, USA 
.RE
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Definition at line 109 of file dlaed5\&.f\&.
.SH "Author"
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Generated automatically by Doxygen for LAPACK from the source code\&.