F06BMF (PDF version)
F06 Chapter Contents
F06 Chapter Introduction
NAG Library Manual

NAG Library Routine Document

F06BMF

Note:  before using this routine, please read the Users' Note for your implementation to check the interpretation of bold italicised terms and other implementation-dependent details.

▸▿ Contents

    1  Purpose
    2  Specification
    3  Description
    4  References
    5  Parameters
    6  Error Indicators and Warnings
    7  Accuracy
    8  Parallelism and Performance
    9  Further Comments
    10  Example

1  Purpose

F06BMF completes the safe computation of the Euclidean length of a vector, following a call to F06FJF or F06KJF.

2  Specification

FUNCTION F06BMF ( SCAL, SSQ)
REAL (KIND=nag_wp) F06BMF
REAL (KIND=nag_wp)  SCAL, SSQ

3  Description

F06BMF completes the safe computation of the Euclidean length of a vector, following a call to F06FJF or F06KJF which return values α and ξ such that
x22=α2ξ.  
F06BMF returns, via the function name, the value
minα⁢ξ,flmax,  
where flmax is the value given by 1/X02AMF.

4  References

None.

5  Parameters

1:     SCAL – REAL (KIND=nag_wp)Input
On entry: the scaling factor α, returned by F06FJF or F06KJF.
Constraint: SCAL≥0.0.
2:     SSQ – REAL (KIND=nag_wp)Input
On entry: the scaled sum of squares ξ, returned by F06FJF or F06KJF.
Constraint: SSQ≥1.0.

6  Error Indicators and Warnings

None.

7  Accuracy

Not applicable.

8  Parallelism and Performance

Not applicable.

9  Further Comments

None.

10  Example

None.
F06BMF (PDF version)
F06 Chapter Contents
F06 Chapter Introduction
NAG Library Manual
© The Numerical Algorithms Group Ltd, Oxford, UK. 2015