NAG Library Function Document

nag_drscl (f06fec)

1  Purpose

2  Specification

3  Description

4  References

5  Arguments

1:    $\mathbf{n}$ – IntegerInput

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

2:    $\mathbf{alpha}$ – doubleInput

On entry: the scalar $\alpha$.

Constraint: $\mathbf{alpha}\ne 0.0$.

3:    $\mathbf{x}\left[\mathit{dim}\right]$ – doubleInput/Output

Note: the dimension, dim, of the array x must be at least $\max \left(1,1+\left(\mathbf{n}-1\right)\times \mathbf{incx}\right)$.

On entry: the $n$-element vector $x$. $x_{\mathit{i}}$ must be stored in $\mathbf{x}\left[1+\left(\mathit{i}-1\right)\times \mathbf{incx}\right]$, for $\mathit{i}=1,2,\dots ,\mathbf{n}$.

Intermediate elements of x are not referenced.

On exit: the updated vector $x$, stored in the same array elements used to supply the original vector.

4:    $\mathbf{incx}$ – IntegerInput

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

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

6  Error Indicators and Warnings

7  Accuracy

8  Parallelism and Performance

9  Further Comments

10  Example