naginterfaces.library.blast.zwaxpby

naginterfaces.library.blast.zwaxpby(alpha, x, beta, y)

zwaxpby computes the sum of two scaled vectors, preserving input, for complex scalars and vectors.

For full information please refer to the NAG Library document for f16gh

https://support.nag.com/numeric/nl/nagdoc_30.3/flhtml/f16/f16ghf.html

Parameters

alphacomplex

The scalar $\alpha$.

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

The $n$-element vector $x$.

If $\text{incx}<0$, $x_{\text{i}}$ must be stored in $x[(n-\text{i})\times \left|\text{incx}\right|]$, for $\text{i}=1,2,\dots ,n$.

If $n=0$, $x$ is not referenced.

betacomplex

The scalar $\beta$.

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

The $n$-element vector $y$.

If $\text{incy}>0$, $y_{\text{i}}$ must be stored in $y[(\text{i}-1)\times \text{incy}]$, for $\text{i}=1,2,\dots ,n$.

If $\text{incy}<0$, $y_{\text{i}}$ must be stored in $y[(n-\text{i})\times \left|\text{incy}\right|]$, for $\text{i}=1,2,\dots ,n$.

Intermediate elements of $y$ are not referenced.

If $\beta =0.0$ or $n=0$, $y$ is not referenced.

Returns

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

The elements $w_i$ of the vector $w$ will be stored in $w$ as follows.

If $\text{incw}>0$, $w_i$ is in $w[(\text{i}-1)\times \text{incw}]$, for $\text{i}=1,2,\dots ,n$.

If $\text{incw}<0$, $w_i$ is in $w[(n-\text{i})\times \left|\text{incw}\right|]$, for $\text{i}=1,2,\dots ,n$.

Intermediate elements of $w$ are not referenced.

Raises

NagValueError

(errno $-4$)

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

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

(errno $-7$)

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

Constraint: $\text{incy}\ne 0$.

(errno $-9$)

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

Constraint: $\text{incw}\ne 0$.

Notes

zwaxpby performs the operation

$$w\leftarrow \alpha x+\beta y\text{,}$$

where $x$ and $y$ are $n$-element complex vectors, and $\alpha$ and $\beta$ are complex scalars.

References

Basic Linear Algebra Subprograms Technical (BLAST) Forum, 2001, Basic Linear Algebra Subprograms Technical (BLAST) Forum Standard, University of Tennessee, Knoxville, Tennessee, https://www.netlib.org/blas/blast-forum/blas-report.pdf