ddoti(3P) Sun Performance Library ddoti(3P)NAMEddoti - Compute the indexed dot product.
SYNOPSIS
DOUBLE PRECISION FUNCTION DDOTI(NZ, X, INDX, Y)
DOUBLE PRECISION X(*), Y(*)
INTEGER NZ
INTEGER INDX(*)
DOUBLE PRECISION FUNCTION DDOTI_64(NZ, X, INDX, Y)
DOUBLE PRECISION X(*), Y(*)
INTEGER*8 NZ
INTEGER*8 INDX(*)
F95 INTERFACE
DOUBLE PRECISION FUNCTION DOTI([NZ], X, INDX, Y)
REAL(8), DIMENSION(:) :: X, Y
INTEGER :: NZ
INTEGER, DIMENSION(:) :: INDX
DOUBLE PRECISION FUNCTION DOTI_64([NZ], X, INDX, Y)
REAL(8), DIMENSION(:) :: X, Y
INTEGER(8) :: NZ
INTEGER(8), DIMENSION(:) :: INDX
C INTERFACE
#include <sunperf.h>
double ddoti (const int nz, const double* x, const int* indx, const
double* y);
double ddoti_64 (const long nz, const double* x, const long* indx,
const double* y);
PURPOSE
DDOTI Compute the indexed dot product of a real sparse vector x stored
in compressed form with a real vector y in full storage form.
dot = 0
do i = 1, n
dot = dot + x(i) * y(indx(i))
enddo
ARGUMENTS
NZ (input)
Number of elements in the compressed form. Unchanged on exit.
X (input)
Vector in compressed form. Unchanged on exit.
INDX (input)
Vector containing the indices of the compressed form. It is
assumed that the elements in INDX are distinct and greater than
zero. Unchanged on exit.
Y (input)
Vector in full storage form. Only the elements corresponding
to the indices in INDX will be accessed.
3rd Berkeley Distribution 6 Mar 2009 ddoti(3P)
