cblas_?doti
cblas_?doti
Computes the dot product of a compressed sparse real vector by a full-storage real vector.
Syntax
float
cblas_sdoti
(
const
MKL_INT
nz
,
const
float
*x
,
const
MKL_INT
*indx
,
const
float
*y
);
double
cblas_ddoti
(
const
MKL_INT
nz
,
const
double
*x
,
const
MKL_INT
*indx
,
const
double
*y
);
Include Files
- mkl.h
Description
The
?doti
routines return the dot product of x
and y
defined as res = x[0]*y[indx[0]] + x[1]*y[indx[1]] +...+ x[nz-1]*y[indx[nz-1]]
where the triple (
nz
, x
, indx
) defines a sparse real vector stored in compressed form, and y
is a real vector in full storage form. The functions reference only the elements of y
whose indices are listed in the array indx
. The values in indx
must be distinct.Input Parameters
- nz
- The number of elements inxandindx.
- x
- Array, size at leastnz.
- indx
- Specifies the indices for the elements ofx.Array, size at leastnz.
- y
- Array, size at least max(indx[i]).
Output Parameters
- res
- Contains the dot product ofxandy, ifnzis positive. Otherwise,rescontains0.