This manual relates to an old release of the Library.
The documentation for the current release is also available on this site.

NAG FL Interface
f06flf (darang)

Settings help

FL Name Style:


FL Specification Language:


1 Purpose

f06flf returns the absolutely largest and absolutely smallest values from a real vector.

2 Specification

Fortran Interface
Subroutine f06flf ( n, x, incx, xmax, xmin)
Integer, Intent (In) :: n, incx
Real (Kind=nag_wp), Intent (In) :: x(*)
Real (Kind=nag_wp), Intent (Out) :: xmax, xmin
C Header Interface
#include <nag.h>
void  f06flf_ (const Integer *n, const double x[], const Integer *incx, double *xmax, double *xmin)
The routine may be called by the names f06flf or nagf_blas_darang.

3 Description

f06flf returns the values xmax and xmin given by
xmax=maxi|xi|,  xmin=mini|xi|,  
where x is an n-element real vector scattered with stride incx. If n<1, then xmax and xmin are returned as zero.

4 References

None.

5 Arguments

1: n Integer Input
On entry: n, the number of elements in x.
2: x(*) Real (Kind=nag_wp) array Input
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.
3: incx Integer Input
On entry: the increment in the subscripts of x between successive elements of x.
Constraint: incx>0.
4: xmax Real (Kind=nag_wp) Output
On exit: the value xmax=maxi|xi|.
5: xmin Real (Kind=nag_wp) Output
On exit: the value xmin=mini|xi|.

6 Error Indicators and Warnings

None.

7 Accuracy

Not applicable.

8 Parallelism and Performance

f06flf is not threaded in any implementation.

9 Further Comments

None.

10 Example

None.