NAG FL Interface
f06fgf (dnegv)

1 Purpose

2 Specification

3 Description

4 References

5 Arguments

1: $\mathbf{n}$ – Integer Input

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

2: $\mathbf{x}\left(*\right)$ – Real (Kind=nag_wp) array Input/Output

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

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

Intermediate elements of x are not referenced.

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

Intermediate elements of x are unchanged.

3: $\mathbf{incx}$ – Integer Input

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