?axpby

Syntax

FORTRAN 77:

call saxpby(n, a, x, incx, b, y, incy)

call daxpby(n, a, x, incx, b, y, incy)

call caxpby(n, a, x, incx, b, y, incy)

call zaxpby(n, a, x, incx, b, y, incy)

FORTRAN 95:

call axpby(x, y [,a] [,b])

Include Files

• FORTRAN 77: mkl_blas.fi
• Fortran 95: blas.f90
• C: mkl_blas.h

Description

The ?axpby routines perform a vector-vector operation defined as
y := a*x + b*y

where:

a and b are scalars

x and y are vectors each with n elements.

Input Parameters

n

INTEGER. Specifies the number of elements in vectors x and y.

a

REAL for saxpby

DOUBLE PRECISION for daxpby

COMPLEX for caxpby

DOUBLE COMPLEX for zaxpby

Specifies the scalar a.

x

REAL for saxpby

DOUBLE PRECISION for daxpby

COMPLEX for caxpby

DOUBLE COMPLEX for zaxpby

Array, DIMENSION at least (1 + (n-1)*abs(incx)).

incx

INTEGER. Specifies the increment for the elements of x.

b

REAL for saxpby

DOUBLE PRECISION for daxpby

COMPLEX for caxpby

DOUBLE COMPLEX for zaxpby

Specifies the scalar b.

y

REAL for saxpby

DOUBLE PRECISION for daxpby

COMPLEX for caxpby

DOUBLE COMPLEX for zaxpby

Array, DIMENSION 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.

Fortran 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 Fortran 95 Interface Conventions.

Specific details for the routine axpby interface are the following:

x

Holds the array of size n.

y

Holds the array of size n.

a

The default value is 1.

b

The default value is 1.