NAG Library Function Document

nag_multiple_conjugate_hermitian (c06gqc)

This is a utility function for use in conjunction with nag_fft_multiple_real (c06fpc) and nag_fft_multiple_hermitian (c06fqc) to calculate inverse discrete Fourier transforms.

4 References

None.

5 Arguments

1: $m$ – IntegerInput: On entry: the number of Hermitian sequences to be conjugated, $m$ .

Constraint: $m \geq 1$ .
2: $n$ – IntegerInput: On entry: the number of data values in each Hermitian sequence, $n$ .

Constraint: $n \geq 1$ .
3: $x [m \times n]$ – doubleInput/Output: On entry: the $m$ data sequences must be stored in x consecutively. If the $n$ data values $z_{j}^{p}$ are written as $x_{j}^{p} + {i y}_{j}^{p}$ , $p = 1, 2, \dots, m$ , then for $0 \leq j \leq n / 2$ , $x_{j}^{p}$ is contained in $x [(p - 1) \times n + j]$ , and for $1 \leq j \leq (n - 1) / 2$ , $y_{j}^{p}$ is contained in $x [(p - 1) \times n + n - j]$ .

On exit: the imaginary parts $y_{j}^{p}$ are negated. The real parts $x_{j}^{p}$ are not referenced.
4: $fail$ – NagError *Input/Output: The NAG error argument (see Section 3.6 in the Essential Introduction).

6 Error Indicators and Warnings

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

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

7 Accuracy

Exact.

8 Parallelism and Performance

Not applicable.

9 Further Comments

None.

10 Example

This program reads in sequences of real data values which are assumed to be Hermitian sequences of complex data stored in Hermitian form. The sequences are expanded into full complex form using nag_multiple_hermitian_to_complex (c06gsc) and printed. The sequences are then conjugated (using nag_multiple_conjugate_hermitian (c06gqc)) and the conjugated sequences are expanded into complex form using nag_multiple_hermitian_to_complex (c06gsc) and printed out.

NAG Library Function Documentnag_multiple_conjugate_hermitian (c06gqc)

▸▿ Contents

1 Purpose

2 Specification

3 Description