NAG Library Routine Document

f06ftf  (dnhous)

1

Purpose

2

Specification

3

Description

4

References

5

Arguments

1:     $\mathbf{n}$ – IntegerInput

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) arrayInput/Output

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

On entry: the original vector $y$.

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

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

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

4:     $\mathbf{incy}$ – IntegerInput

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

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

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

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

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

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

7:     $\mathbf{incz}$ – IntegerInput

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