NAG FL Interface
f06flf (darang)

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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


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


7 Accuracy

Not applicable.

8 Parallelism and Performance

f06flf is not threaded in any implementation.

9 Further Comments


10 Example