397 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			Fortran
		
	
	
	
			
		
		
	
	
			397 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			Fortran
		
	
	
	
| *> \brief \b SGSVTS
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| *
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| *  =========== DOCUMENTATION ===========
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| *
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| * Online html documentation available at 
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| *            http://www.netlib.org/lapack/explore-html/ 
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| *
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| *  Definition:
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| *  ===========
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| *
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| *       SUBROUTINE SGSVTS( M, P, N, A, AF, LDA, B, BF, LDB, U, LDU, V,
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| *                          LDV, Q, LDQ, ALPHA, BETA, R, LDR, IWORK, WORK,
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| *                          LWORK, RWORK, RESULT )
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| * 
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| *       .. Scalar Arguments ..
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| *       INTEGER            LDA, LDB, LDQ, LDR, LDU, LDV, LWORK, M, N, P
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| *       ..
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| *       .. Array Arguments ..
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| *       INTEGER            IWORK( * )
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| *       REAL               A( LDA, * ), AF( LDA, * ), ALPHA( * ),
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| *      $                   B( LDB, * ), BETA( * ), BF( LDB, * ),
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| *      $                   Q( LDQ, * ), R( LDR, * ), RESULT( 6 ),
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| *      $                   RWORK( * ), U( LDU, * ), V( LDV, * ),
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| *      $                   WORK( LWORK )
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| *       ..
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| *  
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| *
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| *> \par Purpose:
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| *  =============
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| *>
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| *> \verbatim
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| *>
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| *> SGSVTS tests SGGSVD, which computes the GSVD of an M-by-N matrix A
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| *> and a P-by-N matrix B:
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| *>              U'*A*Q = D1*R and V'*B*Q = D2*R.
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| *> \endverbatim
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| *
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| *  Arguments:
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| *  ==========
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| *
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| *> \param[in] M
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| *> \verbatim
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| *>          M is INTEGER
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| *>          The number of rows of the matrix A.  M >= 0.
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| *> \endverbatim
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| *>
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| *> \param[in] P
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| *> \verbatim
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| *>          P is INTEGER
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| *>          The number of rows of the matrix B.  P >= 0.
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| *> \endverbatim
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| *>
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| *> \param[in] N
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| *> \verbatim
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| *>          N is INTEGER
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| *>          The number of columns of the matrices A and B.  N >= 0.
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| *> \endverbatim
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| *>
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| *> \param[in] A
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| *> \verbatim
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| *>          A is REAL array, dimension (LDA,M)
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| *>          The M-by-N matrix A.
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| *> \endverbatim
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| *>
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| *> \param[out] AF
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| *> \verbatim
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| *>          AF is REAL array, dimension (LDA,N)
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| *>          Details of the GSVD of A and B, as returned by SGGSVD,
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| *>          see SGGSVD for further details.
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| *> \endverbatim
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| *>
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| *> \param[in] LDA
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| *> \verbatim
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| *>          LDA is INTEGER
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| *>          The leading dimension of the arrays A and AF.
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| *>          LDA >= max( 1,M ).
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| *> \endverbatim
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| *>
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| *> \param[in] B
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| *> \verbatim
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| *>          B is REAL array, dimension (LDB,P)
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| *>          On entry, the P-by-N matrix B.
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| *> \endverbatim
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| *>
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| *> \param[out] BF
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| *> \verbatim
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| *>          BF is REAL array, dimension (LDB,N)
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| *>          Details of the GSVD of A and B, as returned by SGGSVD,
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| *>          see SGGSVD for further details.
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| *> \endverbatim
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| *>
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| *> \param[in] LDB
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| *> \verbatim
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| *>          LDB is INTEGER
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| *>          The leading dimension of the arrays B and BF.
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| *>          LDB >= max(1,P).
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| *> \endverbatim
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| *>
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| *> \param[out] U
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| *> \verbatim
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| *>          U is REAL array, dimension(LDU,M)
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| *>          The M by M orthogonal matrix U.
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| *> \endverbatim
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| *>
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| *> \param[in] LDU
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| *> \verbatim
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| *>          LDU is INTEGER
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| *>          The leading dimension of the array U. LDU >= max(1,M).
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| *> \endverbatim
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| *>
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| *> \param[out] V
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| *> \verbatim
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| *>          V is REAL array, dimension(LDV,M)
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| *>          The P by P orthogonal matrix V.
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| *> \endverbatim
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| *>
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| *> \param[in] LDV
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| *> \verbatim
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| *>          LDV is INTEGER
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| *>          The leading dimension of the array V. LDV >= max(1,P).
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| *> \endverbatim
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| *>
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| *> \param[out] Q
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| *> \verbatim
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| *>          Q is REAL array, dimension(LDQ,N)
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| *>          The N by N orthogonal matrix Q.
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| *> \endverbatim
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| *>
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| *> \param[in] LDQ
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| *> \verbatim
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| *>          LDQ is INTEGER
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| *>          The leading dimension of the array Q. LDQ >= max(1,N).
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| *> \endverbatim
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| *>
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| *> \param[out] ALPHA
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| *> \verbatim
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| *>          ALPHA is REAL array, dimension (N)
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| *> \endverbatim
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| *>
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| *> \param[out] BETA
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| *> \verbatim
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| *>          BETA is REAL array, dimension (N)
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| *>
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| *>          The generalized singular value pairs of A and B, the
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| *>          ``diagonal'' matrices D1 and D2 are constructed from
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| *>          ALPHA and BETA, see subroutine SGGSVD for details.
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| *> \endverbatim
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| *>
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| *> \param[out] R
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| *> \verbatim
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| *>          R is REAL array, dimension(LDQ,N)
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| *>          The upper triangular matrix R.
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| *> \endverbatim
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| *>
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| *> \param[in] LDR
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| *> \verbatim
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| *>          LDR is INTEGER
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| *>          The leading dimension of the array R. LDR >= max(1,N).
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| *> \endverbatim
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| *>
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| *> \param[out] IWORK
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| *> \verbatim
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| *>          IWORK is INTEGER array, dimension (N)
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| *> \endverbatim
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| *>
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| *> \param[out] WORK
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| *> \verbatim
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| *>          WORK is REAL array, dimension (LWORK)
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| *> \endverbatim
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| *>
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| *> \param[in] LWORK
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| *> \verbatim
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| *>          LWORK is INTEGER
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| *>          The dimension of the array WORK,
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| *>          LWORK >= max(M,P,N)*max(M,P,N).
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| *> \endverbatim
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| *>
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| *> \param[out] RWORK
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| *> \verbatim
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| *>          RWORK is REAL array, dimension (max(M,P,N))
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| *> \endverbatim
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| *>
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| *> \param[out] RESULT
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| *> \verbatim
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| *>          RESULT is REAL array, dimension (6)
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| *>          The test ratios:
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| *>          RESULT(1) = norm( U'*A*Q - D1*R ) / ( MAX(M,N)*norm(A)*ULP)
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| *>          RESULT(2) = norm( V'*B*Q - D2*R ) / ( MAX(P,N)*norm(B)*ULP)
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| *>          RESULT(3) = norm( I - U'*U ) / ( M*ULP )
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| *>          RESULT(4) = norm( I - V'*V ) / ( P*ULP )
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| *>          RESULT(5) = norm( I - Q'*Q ) / ( N*ULP )
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| *>          RESULT(6) = 0        if ALPHA is in decreasing order;
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| *>                    = ULPINV   otherwise.
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| *> \endverbatim
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| *
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| *  Authors:
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| *  ========
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| *
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| *> \author Univ. of Tennessee 
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| *> \author Univ. of California Berkeley 
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| *> \author Univ. of Colorado Denver 
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| *> \author NAG Ltd. 
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| *
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| *> \date November 2011
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| *
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| *> \ingroup single_eig
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| *
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| *  =====================================================================
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|       SUBROUTINE SGSVTS( M, P, N, A, AF, LDA, B, BF, LDB, U, LDU, V,
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|      $                   LDV, Q, LDQ, ALPHA, BETA, R, LDR, IWORK, WORK,
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|      $                   LWORK, RWORK, RESULT )
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| *
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| *  -- LAPACK test routine (version 3.4.0) --
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| *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
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| *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
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| *     November 2011
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| *
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| *     .. Scalar Arguments ..
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|       INTEGER            LDA, LDB, LDQ, LDR, LDU, LDV, LWORK, M, N, P
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| *     ..
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| *     .. Array Arguments ..
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|       INTEGER            IWORK( * )
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|       REAL               A( LDA, * ), AF( LDA, * ), ALPHA( * ),
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|      $                   B( LDB, * ), BETA( * ), BF( LDB, * ),
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|      $                   Q( LDQ, * ), R( LDR, * ), RESULT( 6 ),
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|      $                   RWORK( * ), U( LDU, * ), V( LDV, * ),
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|      $                   WORK( LWORK )
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| *     ..
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| *
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| *  =====================================================================
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| *
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| *     .. Parameters ..
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|       REAL               ZERO, ONE
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|       PARAMETER          ( ZERO = 0.0E+0, ONE = 1.0E+0 )
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| *     ..
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| *     .. Local Scalars ..
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|       INTEGER            I, INFO, J, K, L
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|       REAL               ANORM, BNORM, RESID, TEMP, ULP, ULPINV, UNFL
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| *     ..
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| *     .. External Functions ..
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|       REAL               SLAMCH, SLANGE, SLANSY
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|       EXTERNAL           SLAMCH, SLANGE, SLANSY
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| *     ..
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| *     .. External Subroutines ..
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|       EXTERNAL           SCOPY, SGEMM, SGGSVD, SLACPY, SLASET, SSYRK
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| *     ..
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| *     .. Intrinsic Functions ..
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|       INTRINSIC          MAX, MIN, REAL
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| *     ..
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| *     .. Executable Statements ..
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| *
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|       ULP = SLAMCH( 'Precision' )
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|       ULPINV = ONE / ULP
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|       UNFL = SLAMCH( 'Safe minimum' )
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| *
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| *     Copy the matrix A to the array AF.
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| *
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|       CALL SLACPY( 'Full', M, N, A, LDA, AF, LDA )
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|       CALL SLACPY( 'Full', P, N, B, LDB, BF, LDB )
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| *
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|       ANORM = MAX( SLANGE( '1', M, N, A, LDA, RWORK ), UNFL )
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|       BNORM = MAX( SLANGE( '1', P, N, B, LDB, RWORK ), UNFL )
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| *
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| *     Factorize the matrices A and B in the arrays AF and BF.
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| *
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|       CALL SGGSVD( 'U', 'V', 'Q', M, N, P, K, L, AF, LDA, BF, LDB,
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|      $             ALPHA, BETA, U, LDU, V, LDV, Q, LDQ, WORK, IWORK,
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|      $             INFO )
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| *
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| *     Copy R
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| *
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|       DO 20 I = 1, MIN( K+L, M )
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|          DO 10 J = I, K + L
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|             R( I, J ) = AF( I, N-K-L+J )
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|    10    CONTINUE
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|    20 CONTINUE
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| *
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|       IF( M-K-L.LT.0 ) THEN
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|          DO 40 I = M + 1, K + L
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|             DO 30 J = I, K + L
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|                R( I, J ) = BF( I-K, N-K-L+J )
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|    30       CONTINUE
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|    40    CONTINUE
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|       END IF
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| *
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| *     Compute A:= U'*A*Q - D1*R
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| *
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|       CALL SGEMM( 'No transpose', 'No transpose', M, N, N, ONE, A, LDA,
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|      $            Q, LDQ, ZERO, WORK, LDA )
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| *
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|       CALL SGEMM( 'Transpose', 'No transpose', M, N, M, ONE, U, LDU,
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|      $            WORK, LDA, ZERO, A, LDA )
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| *
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|       DO 60 I = 1, K
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|          DO 50 J = I, K + L
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|             A( I, N-K-L+J ) = A( I, N-K-L+J ) - R( I, J )
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|    50    CONTINUE
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|    60 CONTINUE
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| *
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|       DO 80 I = K + 1, MIN( K+L, M )
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|          DO 70 J = I, K + L
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|             A( I, N-K-L+J ) = A( I, N-K-L+J ) - ALPHA( I )*R( I, J )
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|    70    CONTINUE
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|    80 CONTINUE
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| *
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| *     Compute norm( U'*A*Q - D1*R ) / ( MAX(1,M,N)*norm(A)*ULP ) .
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| *
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|       RESID = SLANGE( '1', M, N, A, LDA, RWORK )
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| *
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|       IF( ANORM.GT.ZERO ) THEN
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|          RESULT( 1 ) = ( ( RESID / REAL( MAX( 1, M, N ) ) ) / ANORM ) /
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|      $                 ULP
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|       ELSE
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|          RESULT( 1 ) = ZERO
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|       END IF
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| *
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| *     Compute B := V'*B*Q - D2*R
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| *
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|       CALL SGEMM( 'No transpose', 'No transpose', P, N, N, ONE, B, LDB,
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|      $            Q, LDQ, ZERO, WORK, LDB )
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| *
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|       CALL SGEMM( 'Transpose', 'No transpose', P, N, P, ONE, V, LDV,
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|      $            WORK, LDB, ZERO, B, LDB )
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| *
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|       DO 100 I = 1, L
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|          DO 90 J = I, L
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|             B( I, N-L+J ) = B( I, N-L+J ) - BETA( K+I )*R( K+I, K+J )
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|    90    CONTINUE
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|   100 CONTINUE
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| *
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| *     Compute norm( V'*B*Q - D2*R ) / ( MAX(P,N)*norm(B)*ULP ) .
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| *
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|       RESID = SLANGE( '1', P, N, B, LDB, RWORK )
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|       IF( BNORM.GT.ZERO ) THEN
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|          RESULT( 2 ) = ( ( RESID / REAL( MAX( 1, P, N ) ) ) / BNORM ) /
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|      $                 ULP
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|       ELSE
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|          RESULT( 2 ) = ZERO
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|       END IF
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| *
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| *     Compute I - U'*U
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| *
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|       CALL SLASET( 'Full', M, M, ZERO, ONE, WORK, LDQ )
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|       CALL SSYRK( 'Upper', 'Transpose', M, M, -ONE, U, LDU, ONE, WORK,
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|      $            LDU )
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| *
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| *     Compute norm( I - U'*U ) / ( M * ULP ) .
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| *
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|       RESID = SLANSY( '1', 'Upper', M, WORK, LDU, RWORK )
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|       RESULT( 3 ) = ( RESID / REAL( MAX( 1, M ) ) ) / ULP
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| *
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| *     Compute I - V'*V
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| *
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|       CALL SLASET( 'Full', P, P, ZERO, ONE, WORK, LDV )
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|       CALL SSYRK( 'Upper', 'Transpose', P, P, -ONE, V, LDV, ONE, WORK,
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|      $            LDV )
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| *
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| *     Compute norm( I - V'*V ) / ( P * ULP ) .
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| *
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|       RESID = SLANSY( '1', 'Upper', P, WORK, LDV, RWORK )
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|       RESULT( 4 ) = ( RESID / REAL( MAX( 1, P ) ) ) / ULP
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| *
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| *     Compute I - Q'*Q
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| *
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|       CALL SLASET( 'Full', N, N, ZERO, ONE, WORK, LDQ )
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|       CALL SSYRK( 'Upper', 'Transpose', N, N, -ONE, Q, LDQ, ONE, WORK,
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|      $            LDQ )
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| *
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| *     Compute norm( I - Q'*Q ) / ( N * ULP ) .
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| *
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|       RESID = SLANSY( '1', 'Upper', N, WORK, LDQ, RWORK )
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|       RESULT( 5 ) = ( RESID / REAL( MAX( 1, N ) ) ) / ULP
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| *
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| *     Check sorting
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| *
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|       CALL SCOPY( N, ALPHA, 1, WORK, 1 )
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|       DO 110 I = K + 1, MIN( K+L, M )
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|          J = IWORK( I )
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|          IF( I.NE.J ) THEN
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|             TEMP = WORK( I )
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|             WORK( I ) = WORK( J )
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|             WORK( J ) = TEMP
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|          END IF
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|   110 CONTINUE
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| *
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|       RESULT( 6 ) = ZERO
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|       DO 120 I = K + 1, MIN( K+L, M ) - 1
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|          IF( WORK( I ).LT.WORK( I+1 ) )
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|      $      RESULT( 6 ) = ULPINV
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|   120 CONTINUE
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| *
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|       RETURN
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| *
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| *     End of SGSVTS
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| *
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|       END
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