This is a utility function for use in conjunction with c06fpc and c06fqc. c06gzc initializes the array trig with trigonometric coefficients according to the value of n and must be called prior to the first call of one of the above listed functions.

4 References

None.

5 Arguments

1: $n$ – Integer Input: On entry: the value of $n$ in the Fourier transform function being called.

Constraint: $n \geq 1$ .
2: $trig [2 \times n]$ – double Output: On exit: the trigonometric coefficients are stored in trig.
3: $fail$ – NagError * Input/Output: The NAG error argument (see Section 7 in the Introduction to the NAG Library CL Interface).

6 Error Indicators and Warnings

NE_INT_ARG_LT: On entry, $n = 〈value〉$ .
Constraint: $n \geq 1$ .

7 Accuracy

Exact.

8 Parallelism and Performance

c06gzc is not threaded in any implementation.

9 Further Comments

None.

10 Example

The program reads in 3 real data sequences and prints their discrete Fourier transforms in Hermitian format as calculated by c06fpc. A call is made to c06gzc to initialize the array trig prior to calling c06fpc. The transforms are then printed out in full complex form after a call to c06gsc.

Interfaces: FL CL AD

NAG CL Interface Introduction

C06 (Sum) Chapter Contents

C06 (Sum) Chapter Introduction

c06gz: FL CL AD

NAG CL Interfacec06gzc (init_​trig)

▸▿ Contents

1 Purpose

2 Specification

3 Description

4 References

5 Arguments

6 Error Indicators and Warnings

7 Accuracy

8 Parallelism and Performance

9 Further Comments

10 Example

10.1 Program Text

10.2 Program Data

10.3 Program Results

NAG CL Interface
c06gzc (init_trig)