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authorjulie <julielangou@users.noreply.github.com>2011-10-06 06:53:11 +0000
committerjulie <julielangou@users.noreply.github.com>2011-10-06 06:53:11 +0000
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- SUBROUTINE DLASV2( F, G, H, SSMIN, SSMAX, SNR, CSR, SNL, CSL )
+*> \brief \b DLASV2
*
-* -- LAPACK auxiliary routine (version 3.2) --
-* -- LAPACK is a software package provided by Univ. of Tennessee, --
-* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
-* November 2006
+* =========== DOCUMENTATION ===========
*
-* .. Scalar Arguments ..
- DOUBLE PRECISION CSL, CSR, F, G, H, SNL, SNR, SSMAX, SSMIN
-* ..
+* Online html documentation available at
+* http://www.netlib.org/lapack/explore-html/
+*
+* Definition
+* ==========
*
+* SUBROUTINE DLASV2( F, G, H, SSMIN, SSMAX, SNR, CSR, SNL, CSL )
+*
+* .. Scalar Arguments ..
+* DOUBLE PRECISION CSL, CSR, F, G, H, SNL, SNR, SSMAX, SSMIN
+* ..
+*
* Purpose
* =======
*
-* DLASV2 computes the singular value decomposition of a 2-by-2
-* triangular matrix
-* [ F G ]
-* [ 0 H ].
-* On return, abs(SSMAX) is the larger singular value, abs(SSMIN) is the
-* smaller singular value, and (CSL,SNL) and (CSR,SNR) are the left and
-* right singular vectors for abs(SSMAX), giving the decomposition
-*
-* [ CSL SNL ] [ F G ] [ CSR -SNR ] = [ SSMAX 0 ]
-* [-SNL CSL ] [ 0 H ] [ SNR CSR ] [ 0 SSMIN ].
+*>\details \b Purpose:
+*>\verbatim
+*>
+*> DLASV2 computes the singular value decomposition of a 2-by-2
+*> triangular matrix
+*> [ F G ]
+*> [ 0 H ].
+*> On return, abs(SSMAX) is the larger singular value, abs(SSMIN) is the
+*> smaller singular value, and (CSL,SNL) and (CSR,SNR) are the left and
+*> right singular vectors for abs(SSMAX), giving the decomposition
+*>
+*> [ CSL SNL ] [ F G ] [ CSR -SNR ] = [ SSMAX 0 ]
+*> [-SNL CSL ] [ 0 H ] [ SNR CSR ] [ 0 SSMIN ].
+*>
+*>\endverbatim
*
* Arguments
* =========
*
-* F (input) DOUBLE PRECISION
-* The (1,1) element of the 2-by-2 matrix.
-*
-* G (input) DOUBLE PRECISION
-* The (1,2) element of the 2-by-2 matrix.
-*
-* H (input) DOUBLE PRECISION
-* The (2,2) element of the 2-by-2 matrix.
-*
-* SSMIN (output) DOUBLE PRECISION
-* abs(SSMIN) is the smaller singular value.
-*
-* SSMAX (output) DOUBLE PRECISION
-* abs(SSMAX) is the larger singular value.
+*> \param[in] F
+*> \verbatim
+*> F is DOUBLE PRECISION
+*> The (1,1) element of the 2-by-2 matrix.
+*> \endverbatim
+*>
+*> \param[in] G
+*> \verbatim
+*> G is DOUBLE PRECISION
+*> The (1,2) element of the 2-by-2 matrix.
+*> \endverbatim
+*>
+*> \param[in] H
+*> \verbatim
+*> H is DOUBLE PRECISION
+*> The (2,2) element of the 2-by-2 matrix.
+*> \endverbatim
+*>
+*> \param[out] SSMIN
+*> \verbatim
+*> SSMIN is DOUBLE PRECISION
+*> abs(SSMIN) is the smaller singular value.
+*> \endverbatim
+*>
+*> \param[out] SSMAX
+*> \verbatim
+*> SSMAX is DOUBLE PRECISION
+*> abs(SSMAX) is the larger singular value.
+*> \endverbatim
+*>
+*> \param[out] SNL
+*> \verbatim
+*> SNL is DOUBLE PRECISION
+*> \endverbatim
+*>
+*> \param[out] CSL
+*> \verbatim
+*> CSL is DOUBLE PRECISION
+*> The vector (CSL, SNL) is a unit left singular vector for the
+*> singular value abs(SSMAX).
+*> \endverbatim
+*>
+*> \param[out] SNR
+*> \verbatim
+*> SNR is DOUBLE PRECISION
+*> \endverbatim
+*>
+*> \param[out] CSR
+*> \verbatim
+*> CSR is DOUBLE PRECISION
+*> The vector (CSR, SNR) is a unit right singular vector for the
+*> singular value abs(SSMAX).
+*> \endverbatim
+*>
+*
+* Authors
+* =======
*
-* SNL (output) DOUBLE PRECISION
+*> \author Univ. of Tennessee
+*> \author Univ. of California Berkeley
+*> \author Univ. of Colorado Denver
+*> \author NAG Ltd.
*
-* CSL (output) DOUBLE PRECISION
-* The vector (CSL, SNL) is a unit left singular vector for the
-* singular value abs(SSMAX).
+*> \date November 2011
*
-* SNR (output) DOUBLE PRECISION
+*> \ingroup auxOTHERauxiliary
*
-* CSR (output) DOUBLE PRECISION
-* The vector (CSR, SNR) is a unit right singular vector for the
-* singular value abs(SSMAX).
*
* Further Details
* ===============
+*>\details \b Further \b Details
+*> \verbatim
+*>
+*> Any input parameter may be aliased with any output parameter.
+*>
+*> Barring over/underflow and assuming a guard digit in subtraction, all
+*> output quantities are correct to within a few units in the last
+*> place (ulps).
+*>
+*> In IEEE arithmetic, the code works correctly if one matrix element is
+*> infinite.
+*>
+*> Overflow will not occur unless the largest singular value itself
+*> overflows or is within a few ulps of overflow. (On machines with
+*> partial overflow, like the Cray, overflow may occur if the largest
+*> singular value is within a factor of 2 of overflow.)
+*>
+*> Underflow is harmless if underflow is gradual. Otherwise, results
+*> may correspond to a matrix modified by perturbations of size near
+*> the underflow threshold.
+*>
+*> \endverbatim
+*>
+* =====================================================================
+ SUBROUTINE DLASV2( F, G, H, SSMIN, SSMAX, SNR, CSR, SNL, CSL )
*
-* Any input parameter may be aliased with any output parameter.
-*
-* Barring over/underflow and assuming a guard digit in subtraction, all
-* output quantities are correct to within a few units in the last
-* place (ulps).
-*
-* In IEEE arithmetic, the code works correctly if one matrix element is
-* infinite.
-*
-* Overflow will not occur unless the largest singular value itself
-* overflows or is within a few ulps of overflow. (On machines with
-* partial overflow, like the Cray, overflow may occur if the largest
-* singular value is within a factor of 2 of overflow.)
+* -- LAPACK auxiliary routine (version 3.2) --
+* -- LAPACK is a software package provided by Univ. of Tennessee, --
+* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
+* November 2011
*
-* Underflow is harmless if underflow is gradual. Otherwise, results
-* may correspond to a matrix modified by perturbations of size near
-* the underflow threshold.
+* .. Scalar Arguments ..
+ DOUBLE PRECISION CSL, CSR, F, G, H, SNL, SNR, SSMAX, SSMIN
+* ..
*
* =====================================================================
*