Developer Reference for Intel® oneAPI Math Kernel Library for C
cblas_?roti
Applies Givens rotation to sparse vectors one of which is in compressed form.
Syntax
void cblas_sroti (const MKL_INT nz, float *x, const MKL_INT *indx, float *y, const float c, const float s);
void cblas_droti (const MKL_INT nz, double *x, const MKL_INT *indx, double *y, const double c, const double s);
Include Files
- mkl.h
 
Description
The ?roti routines apply the Givens rotation to elements of two real vectors, x (in compressed form nz, x, indx) and y (in full storage form):
x[i] = c*x[i] + s*y[indx[i]]
y[indx[i]] = c*y[indx[i]]- s*x[i]
The routines 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]).
 - c
 -  
     
A scalar.
 - s
 -  
     
A scalar.
 
Output Parameters
- x and y
 -  
     
The updated arrays.