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Annotation of rpl/lapack/blas/zdotu.f, revision 1.16

1.8       bertrand    1: *> \brief \b ZDOTU
                      2: *
                      3: *  =========== DOCUMENTATION ===========
                      4: *
1.14      bertrand    5: * Online html documentation available at
                      6: *            http://www.netlib.org/lapack/explore-html/
1.8       bertrand    7: *
                      8: *  Definition:
                      9: *  ===========
                     10: *
                     11: *       COMPLEX*16 FUNCTION ZDOTU(N,ZX,INCX,ZY,INCY)
1.14      bertrand   12: *
1.8       bertrand   13: *       .. Scalar Arguments ..
                     14: *       INTEGER INCX,INCY,N
                     15: *       ..
                     16: *       .. Array Arguments ..
                     17: *       COMPLEX*16 ZX(*),ZY(*)
                     18: *       ..
1.14      bertrand   19: *
1.8       bertrand   20: *
                     21: *> \par Purpose:
                     22: *  =============
                     23: *>
                     24: *> \verbatim
                     25: *>
1.12      bertrand   26: *> ZDOTU forms the dot product of two complex vectors
                     27: *>      ZDOTU = X^T * Y
                     28: *>
1.8       bertrand   29: *> \endverbatim
                     30: *
1.15      bertrand   31: *  Arguments:
                     32: *  ==========
                     33: *
                     34: *> \param[in] N
                     35: *> \verbatim
                     36: *>          N is INTEGER
                     37: *>         number of elements in input vector(s)
                     38: *> \endverbatim
                     39: *>
                     40: *> \param[in] ZX
                     41: *> \verbatim
                     42: *>          ZX is REAL array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
                     43: *> \endverbatim
                     44: *>
                     45: *> \param[in] INCX
                     46: *> \verbatim
                     47: *>          INCX is INTEGER
                     48: *>         storage spacing between elements of ZX
                     49: *> \endverbatim
                     50: *>
                     51: *> \param[in] ZY
                     52: *> \verbatim
                     53: *>          ZY is REAL array, dimension ( 1 + ( N - 1 )*abs( INCY ) )
                     54: *> \endverbatim
                     55: *>
                     56: *> \param[in] INCY
                     57: *> \verbatim
                     58: *>          INCY is INTEGER
                     59: *>         storage spacing between elements of ZY
                     60: *> \endverbatim
                     61: *
1.8       bertrand   62: *  Authors:
                     63: *  ========
                     64: *
1.14      bertrand   65: *> \author Univ. of Tennessee
                     66: *> \author Univ. of California Berkeley
                     67: *> \author Univ. of Colorado Denver
                     68: *> \author NAG Ltd.
1.8       bertrand   69: *
1.15      bertrand   70: *> \date November 2017
1.8       bertrand   71: *
                     72: *> \ingroup complex16_blas_level1
                     73: *
                     74: *> \par Further Details:
                     75: *  =====================
                     76: *>
                     77: *> \verbatim
                     78: *>
                     79: *>     jack dongarra, 3/11/78.
                     80: *>     modified 12/3/93, array(1) declarations changed to array(*)
                     81: *> \endverbatim
                     82: *>
                     83: *  =====================================================================
                     84:       COMPLEX*16 FUNCTION ZDOTU(N,ZX,INCX,ZY,INCY)
                     85: *
1.15      bertrand   86: *  -- Reference BLAS level1 routine (version 3.8.0) --
1.8       bertrand   87: *  -- Reference BLAS is a software package provided by Univ. of Tennessee,    --
                     88: *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
1.15      bertrand   89: *     November 2017
1.8       bertrand   90: *
1.1       bertrand   91: *     .. Scalar Arguments ..
                     92:       INTEGER INCX,INCY,N
                     93: *     ..
                     94: *     .. Array Arguments ..
1.8       bertrand   95:       COMPLEX*16 ZX(*),ZY(*)
1.1       bertrand   96: *     ..
                     97: *
                     98: *  =====================================================================
                     99: *
                    100: *     .. Local Scalars ..
1.8       bertrand  101:       COMPLEX*16 ZTEMP
1.1       bertrand  102:       INTEGER I,IX,IY
                    103: *     ..
                    104:       ZTEMP = (0.0d0,0.0d0)
                    105:       ZDOTU = (0.0d0,0.0d0)
                    106:       IF (N.LE.0) RETURN
1.7       bertrand  107:       IF (INCX.EQ.1 .AND. INCY.EQ.1) THEN
                    108: *
                    109: *        code for both increments equal to 1
                    110: *
                    111:          DO I = 1,N
                    112:             ZTEMP = ZTEMP + ZX(I)*ZY(I)
                    113:          END DO
                    114:       ELSE
1.1       bertrand  115: *
                    116: *        code for unequal increments or equal increments
                    117: *          not equal to 1
                    118: *
1.7       bertrand  119:          IX = 1
                    120:          IY = 1
                    121:          IF (INCX.LT.0) IX = (-N+1)*INCX + 1
                    122:          IF (INCY.LT.0) IY = (-N+1)*INCY + 1
                    123:          DO I = 1,N
                    124:             ZTEMP = ZTEMP + ZX(IX)*ZY(IY)
                    125:             IX = IX + INCX
                    126:             IY = IY + INCY
                    127:          END DO
                    128:       END IF
1.1       bertrand  129:       ZDOTU = ZTEMP
                    130:       RETURN
                    131:       END