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.

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

DSDOT

          DSDOT is DOUBLE PRECISION


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

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

November 2011

  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)