NAG Library Routine Document

f06flf (darang)

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 <nagmk26.h>
void  f06flf_ (const Integer *n, const double x[], const Integer *incx, double *xmax, double *xmin)

3
Description

f06flf returns the values xmax and xmin given by
xmax=maxixi,  xmin=minixi,  
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 – IntegerInput
On entry: n, the number of elements in x.
2:     x* – Real (Kind=nag_wp) arrayInput
Note: the dimension of the array x must be at least max1, 1+n-1 ×incx .
On entry: the n-element vector x. xi must be stored in x1+i-1×incx, for i=1,2,,n.
Intermediate elements of x are not referenced.
3:     incx – IntegerInput
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=maxixi.
5:     xmin – Real (Kind=nag_wp)Output
On exit: the value xmin=minixi.

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.