naginterfaces.library.blas.ddiv

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

ddiv computes the quotient of two real scalars.

For full information please refer to the NAG Library document for f06bl

https://support.nag.com/numeric/nl/nagdoc_30.2/flhtml/f06/f06blf.html

Parameters

afloat

The value $a$.

bfloat

The value $b$.

Returns

divfloat

The quotient of the two real scalars.

failbool

$True$ if $a/b$ would overflow (in which case $\left|q\right|=\text{flmax}$) 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.

ddiv returns the value $q$, where

$$\begin{array}{c}q=\{\begin{array}{cc}a/b\text{,}& \text{if}a/b\text{does not overflow,}\\ 0\text{,}& \text{if}a=0\text{,}\\ \text{flmax}\times sign\left(a/b\right)\text{,}& \text{if}a\ne 0\text{and}a/b\text{would overflow.}\end{array}\end{array}$$

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