Visible to Intel only — GUID: GUID-A491FDF5-ACA0-4EDC-8F74-00306D0EBE05
Visible to Intel only — GUID: GUID-A491FDF5-ACA0-4EDC-8F74-00306D0EBE05
?axpy
Computes a vector-scalar product and adds the result to a vector.
Syntax
call saxpy(n, a, x, incx, y, incy)
call daxpy(n, a, x, incx, y, incy)
call caxpy(n, a, x, incx, y, incy)
call zaxpy(n, a, x, incx, y, incy)
call axpy(x, y [,a])
Include Files
- mkl.fi, blas.f90
Description
The ?axpy routines perform a vector-vector operation defined as
y := a*x + y
where:
a is a scalar
x and y are vectors each with a number of elements that equals n.
Input Parameters
- n
-
INTEGER. Specifies the number of elements in vectors x and y.
- a
-
REAL for saxpy
DOUBLE PRECISION for daxpy
COMPLEX for caxpy
DOUBLE COMPLEX for zaxpy
Specifies the scalar a.
- x
-
REAL for saxpy
DOUBLE PRECISION for daxpy
COMPLEX for caxpy
DOUBLE COMPLEX for zaxpy
Array, size at least (1 + (n-1)*abs(incx)).
- incx
-
INTEGER. Specifies the increment for the elements of x.
- y
-
REAL for saxpy
DOUBLE PRECISION for daxpy
COMPLEX for caxpy
DOUBLE COMPLEX for zaxpy
Array, size at least (1 + (n-1)*abs(incy)).
- incy
-
INTEGER. Specifies the increment for the elements of y.
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 axpy interface are the following:
- x
-
Holds the array of size n.
- y
-
Holds the array of size n.
- a
-
The default value is 1.