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Annotation of rpl/lapack/blas/zdotu.f, revision 1.17

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
1.17    ! bertrand   42: *>          ZX is COMPLEX*16 array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
1.15      bertrand   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
1.17    ! bertrand   53: *>          ZY is COMPLEX*16 array, dimension ( 1 + ( N - 1 )*abs( INCY ) )
1.15      bertrand   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: *
                     70: *> \ingroup complex16_blas_level1
                     71: *
                     72: *> \par Further Details:
                     73: *  =====================
                     74: *>
                     75: *> \verbatim
                     76: *>
                     77: *>     jack dongarra, 3/11/78.
                     78: *>     modified 12/3/93, array(1) declarations changed to array(*)
                     79: *> \endverbatim
                     80: *>
                     81: *  =====================================================================
                     82:       COMPLEX*16 FUNCTION ZDOTU(N,ZX,INCX,ZY,INCY)
                     83: *
1.17    ! bertrand   84: *  -- Reference BLAS level1 routine --
1.8       bertrand   85: *  -- Reference BLAS is a software package provided by Univ. of Tennessee,    --
                     86: *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
                     87: *
1.1       bertrand   88: *     .. Scalar Arguments ..
                     89:       INTEGER INCX,INCY,N
                     90: *     ..
                     91: *     .. Array Arguments ..
1.8       bertrand   92:       COMPLEX*16 ZX(*),ZY(*)
1.1       bertrand   93: *     ..
                     94: *
                     95: *  =====================================================================
                     96: *
                     97: *     .. Local Scalars ..
1.8       bertrand   98:       COMPLEX*16 ZTEMP
1.1       bertrand   99:       INTEGER I,IX,IY
                    100: *     ..
                    101:       ZTEMP = (0.0d0,0.0d0)
                    102:       ZDOTU = (0.0d0,0.0d0)
                    103:       IF (N.LE.0) RETURN
1.7       bertrand  104:       IF (INCX.EQ.1 .AND. INCY.EQ.1) THEN
                    105: *
                    106: *        code for both increments equal to 1
                    107: *
                    108:          DO I = 1,N
                    109:             ZTEMP = ZTEMP + ZX(I)*ZY(I)
                    110:          END DO
                    111:       ELSE
1.1       bertrand  112: *
                    113: *        code for unequal increments or equal increments
                    114: *          not equal to 1
                    115: *
1.7       bertrand  116:          IX = 1
                    117:          IY = 1
                    118:          IF (INCX.LT.0) IX = (-N+1)*INCX + 1
                    119:          IF (INCY.LT.0) IY = (-N+1)*INCY + 1
                    120:          DO I = 1,N
                    121:             ZTEMP = ZTEMP + ZX(IX)*ZY(IY)
                    122:             IX = IX + INCX
                    123:             IY = IY + INCY
                    124:          END DO
                    125:       END IF
1.1       bertrand  126:       ZDOTU = ZTEMP
                    127:       RETURN
1.17    ! bertrand  128: *
        !           129: *     End of ZDOTU
        !           130: *
1.1       bertrand  131:       END