dsdot (l) - Linux Manuals

dsdot: accumulation and result

NAME

DSDOT - accumulation and result

SYNOPSIS

DOUBLE PRECISION
FUNCTION DSDOT(N,SX,INCX,SY,INCY)

    
INTEGER INCX,INCY,N

    
REAL SX(*),SY(*)

PURPOSE

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.

ARGUMENTS

N (input) INTEGER
number of elements in input vector(s)
SX (input) REAL array, dimension(N)
single precision vector with N elements
INCX (input) INTEGER
storage spacing between elements of SX
SY (input) REAL array, dimension(N)
single precision vector with N elements
INCY (input) INTEGER
storage spacing between elements of SY
DSDOT (output) DOUBLE PRECISION
DSDOT double precision dot product (zero if N.LE.0)

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)

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