NAG Library Manual, Mark 27.3
Interfaces:  FL   CL   CPP   AD 
NAG FL Interface Introduction
F06 (Blas) Chapter Contents
F06 (Blas) Chapter Introduction
f06cl:  FL   CL   CPP   AD 

NAG FL Interface
f06clf (zdiv)

NAG Library Manual, Mark 27.3
Interfaces:  FL   CL   CPP   AD 
NAG FL Interface Introduction
F06 (Blas) Chapter Contents
F06 (Blas) Chapter Introduction
f06cl:  FL   CL   CPP   AD 

▸▿ Contents

© The Numerical Algorithms Group Ltd. 2021
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1 Purpose

f06clf computes the quotient of two complex scalars.

2 Specification

Fortran Interface
Function f06clf ( a, b, fail)
Complex (Kind=nag_wp) :: f06clf
Complex (Kind=nag_wp), Intent (In) :: a, b
Logical, Intent (Out) :: fail
C Header Interface
#include <nag.h>
Complex  f06clf_ (const Complex *a, const Complex *b, logical *fail)
The routine may be called by the names f06clf or nagf_blas_zdiv.

3 Description

f06clf returns the value q via the function name, where
q= { a/b, if ​a/b​ does not overflow, 0, if ​a=0, cflmax, if ​a≠0​ and ​a/b​ would overflow.  
Here cflmax is a large complex value, given by
cflmax=(flmax×sign(Re(a)/b),flmax×sign(Im(a)/b));  
flmax is the real value given by 1/(x02amf), and for real x, sign(x/0) is taken as sign⁡x.

4 References

None.

5 Arguments

1: a – Complex (Kind=nag_wp) Input
On entry: the value a.
2: b – Complex (Kind=nag_wp) Input
On entry: the value b.
3: fail – Logical Output
On exit: .TRUE. if a/b would overflow (in which case |Re(q)|=|Im(q)|=flmax) or a=b=0 (in which case q=0); otherwise .FALSE..

6 Error Indicators and Warnings

None.

7 Accuracy

Not applicable.

8 Parallelism and Performance

f06clf is not threaded in any implementation.

9 Further Comments

None.

10 Example

None.
NAG Library Manual, Mark 27.3
Interfaces:  FL   CL   CPP   AD 
NAG FL Interface Introduction
F06 (Blas) Chapter Contents
F06 (Blas) Chapter Introduction
f06cl:  FL   CL   CPP   AD 
© The Numerical Algorithms Group Ltd. 2021