http://software.intel.com/sites/products/documentation/hpc/compilerpro/en-us/cpp/win/mkl/refman/index.htm?asum
Computes the sum of magnitudes of the vector elements.
Syntax
FORTRAN 77:
res = sasum(n, x, incx)
res = scasum(n, x, incx)
res = dasum(n, x, incx)
res = dzasum(n, x, incx)
Fortran 95:
res = asum(x)
Description
This routine is declared in mkl_blas.fi for FORTRAN 77 interface, in blas.f90 for Fortran 95 interface, and in mkl_blas.h for C interface.
The ?asum routine computes the sum of the magnitudes of elements of a real vector, or the sum of magnitudes of the real and imaginary parts of elements of a complex vector: res = |Re x(1)| + |Im x(1)| + |Re x(2)| + |Im x(2)|+ ... + |Re x(n)| + |Im x(n)|,
where x is a vector with a number of elements that equals n.
Input Parameters
n
INTEGER. Specifies the number of elements in vector x.
x
REAL for sasum
DOUBLE PRECISION for dasum
COMPLEX for scasum
DOUBLE COMPLEX for dzasum
Array, DIMENSION at least (1 + (n-1)*abs(incx)).
incx
INTEGER. Specifies the increment for indexing vector x.
Output Parameters
res
REAL for sasum
DOUBLE PRECISION for dasum
REAL for scasum
DOUBLE PRECISION for dzasum
Contains the sum of magnitudes of real and imaginary parts of all elements of the vector.
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 asum interface are the following:
x
Holds the array of size n.
Parent topic: BLAS Level 1 Routines