ddot(3P) Sun Performance Library ddot(3P)NAMEddot - compute the dot product of two vectors x and y.
SYNOPSIS
DOUBLE PRECISION FUNCTION DDOT(N, X, INCX, Y, INCY)
INTEGER N, INCX, INCY
DOUBLE PRECISION X(*), Y(*)
DOUBLE PRECISION FUNCTION DDOT_64(N, X, INCX, Y, INCY)
INTEGER*8 N, INCX, INCY
DOUBLE PRECISION X(*), Y(*)
F95 INTERFACE
REAL(8) FUNCTION DOT([N], X, [INCX], Y, [INCY])
INTEGER :: N, INCX, INCY
REAL(8), DIMENSION(:) :: X, Y
REAL(8) FUNCTION DOT_64([N], X, [INCX], Y, [INCY])
INTEGER(8) :: N, INCX, INCY
REAL(8), DIMENSION(:) :: X, Y
C INTERFACE
#include <sunperf.h>
double ddot(int n, double *x, int incx, double *y, int incy);
double ddot_64(long n, double *x, long incx, double *y, long incy);
PURPOSEddot compute the dot product of x and y where x and y are n-vectors.
ARGUMENTS
N (input)
On entry, N specifies the number of elements in the vector.
If N is not positive then the function returns the value 0.0.
Unchanged on exit.
X (input)
( 1 + ( n - 1 )*abs( INCX ) ). On entry, the incremented
array X must contain the vector x. Unchanged on exit.
INCX (input)
On entry, INCX specifies the increment for the elements of X.
Unchanged on exit.
Y (input)
( 1 + ( n - 1 )*abs( INCY ) ). On entry, the incremented
array Y must contain the vector y. Unchanged on exit.
INCY (input)
On entry, INCY specifies the increment for the elements of Y.
Unchanged on exit.
6 Mar 2009 ddot(3P)