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    1: *> \brief \b DLAG2S converts a double precision matrix to a single precision matrix.
    2: *
    3: *  =========== DOCUMENTATION ===========
    4: *
    5: * Online html documentation available at
    6: *            http://www.netlib.org/lapack/explore-html/
    7: *
    8: *> \htmlonly
    9: *> Download DLAG2S + dependencies
   10: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlag2s.f">
   11: *> [TGZ]</a>
   12: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlag2s.f">
   13: *> [ZIP]</a>
   14: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlag2s.f">
   15: *> [TXT]</a>
   16: *> \endhtmlonly
   17: *
   18: *  Definition:
   19: *  ===========
   20: *
   21: *       SUBROUTINE DLAG2S( M, N, A, LDA, SA, LDSA, INFO )
   22: *
   23: *       .. Scalar Arguments ..
   24: *       INTEGER            INFO, LDA, LDSA, M, N
   25: *       ..
   26: *       .. Array Arguments ..
   27: *       REAL               SA( LDSA, * )
   28: *       DOUBLE PRECISION   A( LDA, * )
   29: *       ..
   30: *
   31: *
   32: *> \par Purpose:
   33: *  =============
   34: *>
   35: *> \verbatim
   36: *>
   37: *> DLAG2S converts a DOUBLE PRECISION matrix, A, to a SINGLE
   38: *> PRECISION matrix, SA.
   39: *>
   40: *> RMAX is the overflow for the SINGLE PRECISION arithmetic
   41: *> DLAG2S checks that all the entries of A are between -RMAX and
   42: *> RMAX. If not the conversion is aborted and a flag is raised.
   43: *>
   44: *> This is an auxiliary routine so there is no argument checking.
   45: *> \endverbatim
   46: *
   47: *  Arguments:
   48: *  ==========
   49: *
   50: *> \param[in] M
   51: *> \verbatim
   52: *>          M is INTEGER
   53: *>          The number of lines of the matrix A.  M >= 0.
   54: *> \endverbatim
   55: *>
   56: *> \param[in] N
   57: *> \verbatim
   58: *>          N is INTEGER
   59: *>          The number of columns of the matrix A.  N >= 0.
   60: *> \endverbatim
   61: *>
   62: *> \param[in] A
   63: *> \verbatim
   64: *>          A is DOUBLE PRECISION array, dimension (LDA,N)
   65: *>          On entry, the M-by-N coefficient matrix A.
   66: *> \endverbatim
   67: *>
   68: *> \param[in] LDA
   69: *> \verbatim
   70: *>          LDA is INTEGER
   71: *>          The leading dimension of the array A.  LDA >= max(1,M).
   72: *> \endverbatim
   73: *>
   74: *> \param[out] SA
   75: *> \verbatim
   76: *>          SA is REAL array, dimension (LDSA,N)
   77: *>          On exit, if INFO=0, the M-by-N coefficient matrix SA; if
   78: *>          INFO>0, the content of SA is unspecified.
   79: *> \endverbatim
   80: *>
   81: *> \param[in] LDSA
   82: *> \verbatim
   83: *>          LDSA is INTEGER
   84: *>          The leading dimension of the array SA.  LDSA >= max(1,M).
   85: *> \endverbatim
   86: *>
   87: *> \param[out] INFO
   88: *> \verbatim
   89: *>          INFO is INTEGER
   90: *>          = 0:  successful exit.
   91: *>          = 1:  an entry of the matrix A is greater than the SINGLE
   92: *>                PRECISION overflow threshold, in this case, the content
   93: *>                of SA in exit is unspecified.
   94: *> \endverbatim
   95: *
   96: *  Authors:
   97: *  ========
   98: *
   99: *> \author Univ. of Tennessee
  100: *> \author Univ. of California Berkeley
  101: *> \author Univ. of Colorado Denver
  102: *> \author NAG Ltd.
  103: *
  104: *> \ingroup doubleOTHERauxiliary
  105: *
  106: *  =====================================================================
  107:       SUBROUTINE DLAG2S( M, N, A, LDA, SA, LDSA, INFO )
  108: *
  109: *  -- LAPACK auxiliary routine --
  110: *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
  111: *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
  112: *
  113: *     .. Scalar Arguments ..
  114:       INTEGER            INFO, LDA, LDSA, M, N
  115: *     ..
  116: *     .. Array Arguments ..
  117:       REAL               SA( LDSA, * )
  118:       DOUBLE PRECISION   A( LDA, * )
  119: *     ..
  120: *
  121: *  =====================================================================
  122: *
  123: *     .. Local Scalars ..
  124:       INTEGER            I, J
  125:       DOUBLE PRECISION   RMAX
  126: *     ..
  127: *     .. External Functions ..
  128:       REAL               SLAMCH
  129:       EXTERNAL           SLAMCH
  130: *     ..
  131: *     .. Intrinsic Functions ..
  132:       INTRINSIC          REAL
  133: *     ..
  134: *     .. Executable Statements ..
  135: *
  136:       RMAX = SLAMCH( 'O' )
  137:       DO 20 J = 1, N
  138:          DO 10 I = 1, M
  139:             IF( ( A( I, J ).LT.-RMAX ) .OR. ( A( I, J ).GT.RMAX ) ) THEN
  140:                INFO = 1
  141:                GO TO 30
  142:             END IF
  143:             SA( I, J ) = REAL( A( I, J ) )
  144:    10    CONTINUE
  145:    20 CONTINUE
  146:       INFO = 0
  147:    30 CONTINUE
  148:       RETURN
  149: *
  150: *     End of DLAG2S
  151: *
  152:       END