NAG FL Interface
f06edf (dscal)

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FL Specification Language:

1 Purpose

f06edf multiplies a real vector by a real scalar.

2 Specification

Fortran Interface
Subroutine f06edf ( n, alpha, x, incx)
Integer, Intent (In) :: n, incx
Real (Kind=nag_wp), Intent (In) :: alpha
Real (Kind=nag_wp), Intent (Inout) :: x(*)
C Header Interface
#include <nag.h>
void  f06edf_ (const Integer *n, const double *alpha, double x[], const Integer *incx)
The routine may be called by the names f06edf, nagf_blas_dscal or its BLAS name dscal.

3 Description

f06edf performs the operation
where x is an n-element real vector scattered with stride incx, and α is a real scalar.

4 References

Lawson C L, Hanson R J, Kincaid D R and Krogh F T (1979) Basic linear algebra supbrograms for Fortran usage ACM Trans. Math. Software 5 308–325

5 Arguments

1: n Integer Input
On entry: n, the number of elements in x.
2: alpha Real (Kind=nag_wp) Input
On entry: the scalar α.
3: x(*) Real (Kind=nag_wp) array Input/Output
Note: the dimension of the array x must be at least max(1, 1+(n-1) ×incx ) .
On entry: the n-element vector x. xi must be stored in x(1+(i-1)×incx), for i=1,2,,n.
Intermediate elements of x are not referenced.
On exit: the vector αx stored in the array elements used to supply the original vector x.
Intermediate elements of x are unchanged.
4: incx Integer Input
On entry: the increment in the subscripts of x between successive elements of x.
Constraint: incx>0.

6 Error Indicators and Warnings


7 Accuracy

Not applicable.

8 Parallelism and Performance

f06edf is not threaded in any implementation.

9 Further Comments


10 Example