NAG FL Interface
f16ehf (dwaxpby)

1 Purpose

2 Specification

3 Description

4 References

5 Arguments

1: $\mathbf{n}$ – Integer Input

On entry: $n$, the number of elements in $x$, $y$ and $w$.

2: $\mathbf{alpha}$ – Real (Kind=nag_wp) Input

On entry: the scalar $\alpha$.

3: $\mathbf{x}\left(1+(\mathbf{n}-1)\times \left|\mathbf{incx}\right|\right)$ – Real (Kind=nag_wp) array Input

On entry: the $n$-element vector $x$.

If $\mathbf{incx}>0$, $x_{\mathit{i}}$ must be stored in $\mathbf{x}\left((\mathit{i}-1)\times \mathbf{incx}+1\right)$, for $\mathit{i}=1,2,\dots ,\mathbf{n}$.

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

Intermediate elements of x are not referenced. If $\mathbf{n}=0$, x is not referenced.

4: $\mathbf{incx}$ – Integer Input

On entry: the increment in the subscripts of x between successive elements of $x$.

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

5: $\mathbf{beta}$ – Real (Kind=nag_wp) Input

On entry: the scalar $\beta$.

6: $\mathbf{y}\left(1+(\mathbf{n}-1)\times \left|\mathbf{incy}\right|\right)$ – Real (Kind=nag_wp) array Input

On entry: the $n$-element vector $y$.

If $\mathbf{incy}>0$, $y_{\mathit{i}}$ must be stored in $\mathbf{y}\left((\mathit{i}-1)\times \mathbf{incy}+1\right)$, for $\mathit{i}=1,2,\dots ,\mathbf{n}$.

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

Intermediate elements of y are not referenced. If $\beta =0.0$ or $\mathbf{n}=0$, y is not referenced.

7: $\mathbf{incy}$ – Integer Input

On entry: the increment in the subscripts of y between successive elements of $y$.

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

8: $\mathbf{w}\left(1+(\mathbf{n}-1)\times \left|\mathbf{incw}\right|\right)$ – Real (Kind=nag_wp) array Input/Output

On entry: if $\left|\mathbf{incw}\right|\ne 1$, intermediate elements of w may contain values and will not be referenced; the other elements will be overwritten and need not be set.

On exit: the elements $w_i$ of the vector $w$ will be stored in w as follows.

If $\mathbf{incw}>0$, $w_i$ is in $\mathbf{w}\left((\mathit{i}-1)\times \mathbf{incw}+1\right)$, for $\mathit{i}=1,2,\dots ,\mathbf{n}$.

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

Intermediate elements of w are not referenced.

9: $\mathbf{incw}$ – Integer Input

On entry: the increment in the subscripts of w between successive elements of $w$.

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

6 Error Indicators and Warnings

7 Accuracy

8 Parallelism and Performance

9 Further Comments

10 Example

10.1 Program Text

10.2 Program Data

10.3 Program Results