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*> \brief \b DLAG2S converts a double precision matrix to a single precision matrix.
*
* =========== DOCUMENTATION ===========
*
* Online html documentation available at
* http://www.netlib.org/lapack/explore-html/
*
*> \htmlonly
*> Download DLAG2S + dependencies
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlag2s.f">
*> [TGZ]</a>
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlag2s.f">
*> [ZIP]</a>
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlag2s.f">
*> [TXT]</a>
*> \endhtmlonly
*
* Definition:
* ===========
*
* SUBROUTINE DLAG2S( M, N, A, LDA, SA, LDSA, INFO )
*
* .. Scalar Arguments ..
* INTEGER INFO, LDA, LDSA, M, N
* ..
* .. Array Arguments ..
* REAL SA( LDSA, * )
* DOUBLE PRECISION A( LDA, * )
* ..
*
*
*> \par Purpose:
* =============
*>
*> \verbatim
*>
*> DLAG2S converts a DOUBLE PRECISION matrix, SA, to a SINGLE
*> PRECISION matrix, A.
*>
*> RMAX is the overflow for the SINGLE PRECISION arithmetic
*> DLAG2S checks that all the entries of A are between -RMAX and
*> RMAX. If not the conversion is aborted and a flag is raised.
*>
*> This is an auxiliary routine so there is no argument checking.
*> \endverbatim
*
* Arguments:
* ==========
*
*> \param[in] M
*> \verbatim
*> M is INTEGER
*> The number of lines of the matrix A. M >= 0.
*> \endverbatim
*>
*> \param[in] N
*> \verbatim
*> N is INTEGER
*> The number of columns of the matrix A. N >= 0.
*> \endverbatim
*>
*> \param[in] A
*> \verbatim
*> A is DOUBLE PRECISION array, dimension (LDA,N)
*> On entry, the M-by-N coefficient matrix A.
*> \endverbatim
*>
*> \param[in] LDA
*> \verbatim
*> LDA is INTEGER
*> The leading dimension of the array A. LDA >= max(1,M).
*> \endverbatim
*>
*> \param[out] SA
*> \verbatim
*> SA is REAL array, dimension (LDSA,N)
*> On exit, if INFO=0, the M-by-N coefficient matrix SA; if
*> INFO>0, the content of SA is unspecified.
*> \endverbatim
*>
*> \param[in] LDSA
*> \verbatim
*> LDSA is INTEGER
*> The leading dimension of the array SA. LDSA >= max(1,M).
*> \endverbatim
*>
*> \param[out] INFO
*> \verbatim
*> INFO is INTEGER
*> = 0: successful exit.
*> = 1: an entry of the matrix A is greater than the SINGLE
*> PRECISION overflow threshold, in this case, the content
*> of SA in exit is unspecified.
*> \endverbatim
*
* Authors:
* ========
*
*> \author Univ. of Tennessee
*> \author Univ. of California Berkeley
*> \author Univ. of Colorado Denver
*> \author NAG Ltd.
*
*> \date September 2012
*
*> \ingroup doubleOTHERauxiliary
*
* =====================================================================
SUBROUTINE DLAG2S( M, N, A, LDA, SA, LDSA, INFO )
*
* -- LAPACK auxiliary routine (version 3.4.2) --
* -- LAPACK is a software package provided by Univ. of Tennessee, --
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
* September 2012
*
* .. Scalar Arguments ..
INTEGER INFO, LDA, LDSA, M, N
* ..
* .. Array Arguments ..
REAL SA( LDSA, * )
DOUBLE PRECISION A( LDA, * )
* ..
*
* =====================================================================
*
* .. Local Scalars ..
INTEGER I, J
DOUBLE PRECISION RMAX
* ..
* .. External Functions ..
REAL SLAMCH
EXTERNAL SLAMCH
* ..
* .. Executable Statements ..
*
RMAX = SLAMCH( 'O' )
DO 20 J = 1, N
DO 10 I = 1, M
IF( ( A( I, J ).LT.-RMAX ) .OR. ( A( I, J ).GT.RMAX ) ) THEN
INFO = 1
GO TO 30
END IF
SA( I, J ) = A( I, J )
10 CONTINUE
20 CONTINUE
INFO = 0
30 CONTINUE
RETURN
*
* End of DLAG2S
*
END
|
