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Annotation of rpl/lapack/lapack/zlag2c.f, revision 1.19

1.12      bertrand    1: *> \brief \b ZLAG2C converts a complex double precision matrix to a complex single precision matrix.
1.9       bertrand    2: *
                      3: *  =========== DOCUMENTATION ===========
                      4: *
1.16      bertrand    5: * Online html documentation available at
                      6: *            http://www.netlib.org/lapack/explore-html/
1.9       bertrand    7: *
                      8: *> \htmlonly
1.16      bertrand    9: *> Download ZLAG2C + dependencies
                     10: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/zlag2c.f">
                     11: *> [TGZ]</a>
                     12: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/zlag2c.f">
                     13: *> [ZIP]</a>
                     14: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/zlag2c.f">
1.9       bertrand   15: *> [TXT]</a>
1.16      bertrand   16: *> \endhtmlonly
1.9       bertrand   17: *
                     18: *  Definition:
                     19: *  ===========
                     20: *
                     21: *       SUBROUTINE ZLAG2C( M, N, A, LDA, SA, LDSA, INFO )
1.16      bertrand   22: *
1.9       bertrand   23: *       .. Scalar Arguments ..
                     24: *       INTEGER            INFO, LDA, LDSA, M, N
                     25: *       ..
                     26: *       .. Array Arguments ..
                     27: *       COMPLEX            SA( LDSA, * )
                     28: *       COMPLEX*16         A( LDA, * )
                     29: *       ..
1.16      bertrand   30: *
1.9       bertrand   31: *
                     32: *> \par Purpose:
                     33: *  =============
                     34: *>
                     35: *> \verbatim
                     36: *>
                     37: *> ZLAG2C converts a COMPLEX*16 matrix, SA, to a COMPLEX matrix, A.
                     38: *>
                     39: *> RMAX is the overflow for the SINGLE PRECISION arithmetic
                     40: *> ZLAG2C checks that all the entries of A are between -RMAX and
1.16      bertrand   41: *> RMAX. If not the conversion is aborted and a flag is raised.
1.9       bertrand   42: *>
                     43: *> This is an auxiliary routine so there is no argument checking.
                     44: *> \endverbatim
                     45: *
                     46: *  Arguments:
                     47: *  ==========
                     48: *
                     49: *> \param[in] M
                     50: *> \verbatim
                     51: *>          M is INTEGER
                     52: *>          The number of lines of the matrix A.  M >= 0.
                     53: *> \endverbatim
                     54: *>
                     55: *> \param[in] N
                     56: *> \verbatim
                     57: *>          N is INTEGER
                     58: *>          The number of columns of the matrix A.  N >= 0.
                     59: *> \endverbatim
                     60: *>
                     61: *> \param[in] A
                     62: *> \verbatim
                     63: *>          A is COMPLEX*16 array, dimension (LDA,N)
                     64: *>          On entry, the M-by-N coefficient matrix A.
                     65: *> \endverbatim
                     66: *>
                     67: *> \param[in] LDA
                     68: *> \verbatim
                     69: *>          LDA is INTEGER
                     70: *>          The leading dimension of the array A.  LDA >= max(1,M).
                     71: *> \endverbatim
                     72: *>
                     73: *> \param[out] SA
                     74: *> \verbatim
                     75: *>          SA is COMPLEX array, dimension (LDSA,N)
                     76: *>          On exit, if INFO=0, the M-by-N coefficient matrix SA; if
                     77: *>          INFO>0, the content of SA is unspecified.
                     78: *> \endverbatim
                     79: *>
                     80: *> \param[in] LDSA
                     81: *> \verbatim
                     82: *>          LDSA is INTEGER
                     83: *>          The leading dimension of the array SA.  LDSA >= max(1,M).
                     84: *> \endverbatim
                     85: *>
                     86: *> \param[out] INFO
                     87: *> \verbatim
                     88: *>          INFO is INTEGER
                     89: *>          = 0:  successful exit.
                     90: *>          = 1:  an entry of the matrix A is greater than the SINGLE
                     91: *>                PRECISION overflow threshold, in this case, the content
                     92: *>                of SA in exit is unspecified.
                     93: *> \endverbatim
                     94: *
                     95: *  Authors:
                     96: *  ========
                     97: *
1.16      bertrand   98: *> \author Univ. of Tennessee
                     99: *> \author Univ. of California Berkeley
                    100: *> \author Univ. of Colorado Denver
                    101: *> \author NAG Ltd.
1.9       bertrand  102: *
                    103: *> \ingroup complex16OTHERauxiliary
                    104: *
                    105: *  =====================================================================
1.1       bertrand  106:       SUBROUTINE ZLAG2C( M, N, A, LDA, SA, LDSA, INFO )
                    107: *
1.19    ! bertrand  108: *  -- LAPACK auxiliary routine --
1.1       bertrand  109: *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
                    110: *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
                    111: *
                    112: *     .. Scalar Arguments ..
                    113:       INTEGER            INFO, LDA, LDSA, M, N
                    114: *     ..
                    115: *     .. Array Arguments ..
                    116:       COMPLEX            SA( LDSA, * )
                    117:       COMPLEX*16         A( LDA, * )
                    118: *     ..
                    119: *
1.8       bertrand  120: *  =====================================================================
1.1       bertrand  121: *
                    122: *     .. Local Scalars ..
                    123:       INTEGER            I, J
                    124:       DOUBLE PRECISION   RMAX
                    125: *     ..
                    126: *     .. Intrinsic Functions ..
1.19    ! bertrand  127:       INTRINSIC          DBLE, DIMAG, CMPLX
1.1       bertrand  128: *     ..
                    129: *     .. External Functions ..
                    130:       REAL               SLAMCH
                    131:       EXTERNAL           SLAMCH
                    132: *     ..
                    133: *     .. Executable Statements ..
                    134: *
                    135:       RMAX = SLAMCH( 'O' )
                    136:       DO 20 J = 1, N
                    137:          DO 10 I = 1, M
                    138:             IF( ( DBLE( A( I, J ) ).LT.-RMAX ) .OR.
1.8       bertrand  139:      $          ( DBLE( A( I, J ) ).GT.RMAX ) .OR.
                    140:      $          ( DIMAG( A( I, J ) ).LT.-RMAX ) .OR.
                    141:      $          ( DIMAG( A( I, J ) ).GT.RMAX ) ) THEN
1.1       bertrand  142:                INFO = 1
                    143:                GO TO 30
                    144:             END IF
1.19    ! bertrand  145:             SA( I, J ) = CMPLX( A( I, J ) )
1.1       bertrand  146:    10    CONTINUE
                    147:    20 CONTINUE
                    148:       INFO = 0
                    149:    30 CONTINUE
                    150:       RETURN
                    151: *
                    152: *     End of ZLAG2C
                    153: *
                    154:       END