Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
?axpyi
Adds a scalar multiple of compressed sparse vector to a full-storage vector.
Syntax
call saxpyi ( nz, a, x, indx, y )
call daxpyi ( nz, a, x, indx, y )
call caxpyi ( nz, a, x, indx, y )
call zaxpyi ( nz, a, x, indx, y )
call axpyi ( x, indx, y [ , a ] )
Include Files
mkl.fi , mkl_blas.f90
Description
The ?axpyi routines perform a vector-vector operation defined as
\[y \leftarrow a \cdot x + y\]
where:
\(a\) is a scalar,
\(x\) is a sparse vector stored in compressed form,
\(y\) is a vector in full storage form.
The ?axpyi routines reference or modify only the elements of y whose indices are listed in the array indx .
Input Parameters
nz
INTEGER .
The number of elements in x and indx .
a
REAL |
for saxpyi |
DOUBLE PRECISION |
for daxpyi |
COMPLEX |
for caxpyi |
DOUBLE COMPLEX |
for zaxpyi |
Specifies the scalar \(a\) .
x
REAL |
for saxpyi |
DOUBLE PRECISION |
for daxpyi |
COMPLEX |
for caxpyi |
DOUBLE COMPLEX |
for zaxpyi |
Array, size at least nz .
indx
INTEGER.
Specifies the indices for the elements of x. Array, size at least nz .
y
REAL |
for saxpyi |
DOUBLE PRECISION |
for daxpyi |
COMPLEX |
for caxpyi |
DOUBLE COMPLEX |
for zaxpyi |
Array, size at least \(\max(\text{indx}(i))\).
Output Parameters
- y
-
Contains the updated vector \(y\) .
BLAS 95 Interface Notes
Routines in Fortran 95 interface have fewer arguments in the calling sequence than their FORTRAN 77 counterparts. For general conventions applied to skip redundant or reconstructible arguments, see BLAS 95 Interface Conventions .
Specific details for the routine axpyi interface are the following:
- x
-
Holds the vector with the number of elements nz .
- indx
-
Holds the vector with the number of elements nz .
- y
-
Holds the vector with the number of elements nz .
- a
-
The default value is 1.