This is a utility function for use in conjunction with nag_fft_multiple_real (c06fpc) and nag_fft_multiple_hermitian (c06fqc). nag_fft_init_trig (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:
– IntegerInput
On entry: the value of in the Fourier transform function being called.
Constraint:
.
2:
– doubleOutput
On exit: the trigonometric coefficients are stored in trig.
3:
– 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_INT_ARG_LT
On entry, .
Constraint: .
7
Accuracy
Exact.
8
Parallelism and Performance
nag_fft_init_trig (c06gzc) is not threaded in any implementation.