naginterfaces.library.blas.zdiv

naginterfaces.library.blas.zdiv(a, b)

zdiv computes the quotient of two complex scalars.

For full information please refer to the NAG Library document for f06cl

https://support.nag.com/numeric/nl/nagdoc_30.2/flhtml/f06/f06clf.html

Parameters

acomplex

The value $a$.

bcomplex

The value $b$.

Returns

sdivcomplex

The value $q$.

failbool

$True$ if $a/b$ would overflow (in which case $\left|Re\left(q\right)\right|=\left|Im\left(q\right)\right|=\text{flmax}$) or $a=b=0$ (in which case $q=0$); otherwise $False$.

Notes

No equivalent traditional C interface for this routine exists in the NAG Library.

zdiv returns the value $q$, where

$$\begin{array}{c}q=\{\begin{array}{cc}a/b\text{,}& \text{if}a/b\text{does not overflow,}\\ 0\text{,}& \text{if}a=0\text{,}\\ \text{cflmax}\text{,}& \text{if}a\ne 0\text{and}a/b\text{would overflow.}\end{array}\end{array}$$

Here $\text{cflmax}$ is a large complex value, given by

$$\text{cflmax}=(\text{flmax}\times sign\left(Re\left(a\right)/b\right),\text{flmax}\times sign\left(Im\left(a\right)/b\right))\text{;}$$

$\text{flmax}$ is the float value given by $1/\left(\text{machine.real\_safe}\right)$, and for float $x$, $sign\left(x/0\right)$ is taken as $sign\left(x\right)$.