NAG C Library Function Document

nag_sum_fft_qtrsine (c06rgc)

1

Purpose

2

Specification

3

Description

4

References

5

Arguments

1:    $\mathbf{direct}$ – Nag_TransformDirectionInput

On entry: indicates the transform, as defined in Section 3, to be computed.

$\mathbf{direct}=\mathrm{Nag\_ForwardTransform}$

Forward transform.

$\mathbf{direct}=\mathrm{Nag\_BackwardTransform}$

Inverse transform.

Constraint: $\mathbf{direct}=\mathrm{Nag\_ForwardTransform}$ or $\mathrm{Nag\_BackwardTransform}$.

2:    $\mathbf{m}$ – IntegerInput

On entry: $m$, the number of sequences to be transformed.

Constraint: $\mathbf{m}\ge 1$.

3:    $\mathbf{n}$ – IntegerInput

On entry: $n$, the number of real values in each sequence.

Constraint: $\mathbf{n}\ge 1$.

4:    $\mathbf{x}\left[\mathbf{n}\times \mathbf{m}\right]$ – doubleInput/Output

On entry: the $m$ data sequences to be transformed. The $\mathit{p}$th sequence to be transformed, denoted by $x_{\mathit{j}}^{\mathit{p}}$, for $\mathit{j}=1,2,\dots ,n$ and $\mathit{p}=1,2,\dots ,m$, must be stored in $\mathbf{x}\left[\left(p-1\right)\times \mathbf{n}+j-1\right]$.

On exit: the $m$ quarter-wave sine transforms, overwriting the corresponding original sequences. The $n$ components of the $\mathit{p}$th quarter-wave sine transform, denoted by ${\hat{x}}_{\mathit{k}}^{\mathit{p}}$, for $\mathit{k}=1,2,\dots ,n$ and $\mathit{p}=1,2,\dots ,m$, are stored in $\mathbf{x}\left[\left(p-1\right)\times \mathbf{n}+k-1\right]$.

5:    $\mathbf{fail}$ – NagError *Input/Output

The NAG error argument (see Section 3.7 in How to Use the NAG Library and its Documentation).

6

Error Indicators and Warnings

NE_ALLOC_FAIL

Dynamic memory allocation failed.
See Section 2.3.1.2 in How to Use the NAG Library and its Documentation for further information.

NE_BAD_PARAM

On entry, argument $〈\mathit{\text{value}}〉$ had an illegal value.

NE_INT

On entry, $\mathbf{m}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{m}\ge 1$.

On entry, $\mathbf{n}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{n}\ge 1$.

NE_INTERNAL_ERROR

An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact NAG for assistance.

An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact NAG for assistance.
See Section 2.7.6 in How to Use the NAG Library and its Documentation for further information.

NE_NO_LICENCE

Your licence key may have expired or may not have been installed correctly.
See Section 2.7.5 in How to Use the NAG Library and its Documentation for further information.

7

Accuracy

8

Parallelism and Performance

9

Further Comments

10

Example

10.1

Program Text

Program Text (c06rgce.c)

10.2

Program Data

Program Data (c06rgce.d)

10.3

Program Results

Program Results (c06rgce.r)