naginterfaces.library.blas.drscl

naginterfaces.library.blas.drscl(alpha, x)

drscl multiplies a real vector by the reciprocal of a scalar.

For full information please refer to the NAG Library document for f06fe

https://support.nag.com/numeric/nl/nagdoc_30.2/flhtml/f06/f06fef.html

Parameters

alphafloat

The scalar $\alpha$.

xfloat, array-like, shape $\left(n\right)$

The $n$-element vector $x$.

Returns

xfloat, ndarray, shape $\left(n\right)$

The updated vector $x$.

Raises

NagValueError

(errno $2$)

On entry, error in parameter $alpha$.

Constraint: $alpha\ne 0.0$.

(errno $4$)

On entry, error in parameter $\text{incx}$.

Constraint: $\text{incx}>0$.

Notes

drscl performs the operation

$$x\leftarrow \frac{1}{\alpha }x$$

where $x$ is an $n$-element real vector and $\alpha$ is a real nonzero scalar.