NAG Library Routine Document

F06CLF

+− Contents

1 Purpose

9 Example

F06CLF computes the quotient of two complex scalars.

FUNCTION F06CLF (

COMPLEX (KIND=nag_wp) F06CLF

COMPLEX (KIND=nag_wp)	A, B
LOGICAL	FAIL

F06CLF returns the value

q

via the function name, where

q = \{\begin{cases} a / b, & if ​ a / b ​ does not overflow, \\ 0, & if ​ a = 0, \\ cflmax, & if ​ a \neq 0 ​ and ​ a / b ​ would overflow. \end{cases}

Here

cflmax

is a large complex value, given by

cflmax = (flmax \times sign (Re (a) / b), flmax \times 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

None.

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 – LOGICALOutput: 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..