Developer Reference for Intel® oneAPI Math Kernel Library for C
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 in x and indx .
 - x
 -  
     
Array, size at least nz.
 - indx
 -  
     
Specifies the indices for the elements of x.
Array, size at least nz.
 - y
 -  
     
Array, size at least max(indx[i]).
 
Output Parameters
- res
 -  
     
Contains the dot product of x and y, if nz is positive. Otherwise, res contains 0.