table of contents
DSDOT(1) | BLAS routine | DSDOT(1) |
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)
November 2008 | BLAS routine |