NAG FL Interface
f06ftf (dnhous)

1 Purpose

2 Specification

3 Description

4 References

5 Arguments

1: $\mathbf{n}$ – Integer Input

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

2: $\mathbf{delta}$ – Real (Kind=nag_wp) Input/Output

On entry: the original scalar $\delta$.

On exit: the transformed scalar $\delta$.

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

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

On entry: the original vector $y$.

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

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

On exit: the transformed vector stored in the same array elements used to supply the original vector $y$.

4: $\mathbf{incy}$ – Integer Input

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

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

On entry: the scalar $\zeta$, as returned by f06frf.

If $\zeta =0$, $P$ is assumed to be the unit matrix and the transformation is skipped.

Constraint: if $\mathbf{n}=0$, $\mathbf{zeta}=0.0$.

6: $\mathbf{z}\left(*\right)$ – Real (Kind=nag_wp) array Input

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

On entry: the vector $z$, as returned by f06frf.

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

If $\mathbf{incz}<0$, $z_{\mathit{i}}$ must be stored in $\mathbf{z}\left(1-(\mathbf{n}-\mathit{i})\times \mathbf{incz}\right)$, for $\mathit{i}=1,2,\dots ,\mathbf{n}$.

7: $\mathbf{incz}$ – Integer Input

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

6 Error Indicators and Warnings

7 Accuracy

8 Parallelism and Performance

9 Further Comments

10 Example