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dsdot.f(3) LAPACK dsdot.f(3)

NAME

dsdot.f

SYNOPSIS

Functions/Subroutines


double precision function dsdot (N, SX, INCX, SY, INCY)
DSDOT

Function/Subroutine Documentation

double precision function dsdot (integer N, real, dimension(*) SX, integer INCX, real, dimension(*) SY, integer INCY)

DSDOT

Purpose:


Compute the inner product of two vectors with extended
precision accumulation and result.
Returns D.P. dot product accumulated in D.P., for S.P. SX and SY
DSDOT = sum for I = 0 to N-1 of SX(LX+I*INCX) * SY(LY+I*INCY),
where LX = 1 if INCX .GE. 0, else LX = 1+(1-N)*INCX, and LY is
defined in a similar way using INCY.

Parameters:

N


N is INTEGER
number of elements in input vector(s)

SX


SX is REAL array, dimension(N)
single precision vector with N elements

INCX


INCX is INTEGER
storage spacing between elements of SX

SY


SY is REAL array, dimension(N)
single precision vector with N elements

INCY


INCY is INTEGER
storage spacing between elements of SY

Returns:

DSDOT


DSDOT is DOUBLE PRECISION
DSDOT double precision dot product (zero if N.LE.0)

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

December 2016

Further Details:


References:


C. L. Lawson, R. J. Hanson, D. R. Kincaid and F. T.
Krogh, Basic linear algebra subprograms for Fortran
usage, Algorithm No. 539, Transactions on Mathematical
Software 5, 3 (September 1979), pp. 308-323.
REVISION HISTORY (YYMMDD)
791001 DATE WRITTEN
890831 Modified array declarations. (WRB)
890831 REVISION DATE from Version 3.2
891214 Prologue converted to Version 4.0 format. (BAB)
920310 Corrected definition of LX in DESCRIPTION. (WRB)
920501 Reformatted the REFERENCES section. (WRB)
070118 Reformat to LAPACK style (JL)

Definition at line 121 of file dsdot.f.

Author

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