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SINFIT
Computes an approximate periodogram of 1D data which may be
irregularly spaced, by weighted least squares fitting of sine
waves. Bad quality data are omitted from the calculation. The
program calculates:-
fit(frequency) = amplitude * SIN(frequency*angle + phase)
- mean value of data
The normalisation used for the power is:-
power = (amplitude / 2)**2
Since the fast Fourier transform is not used, the program can be
slow for large data sets, and so should be run in batch.
A data object containing the power at each frequency is created.
NOTE: if SINFIT is run on regularly spaced data, it
will not give a sensible result at the Nyquist
frequency (= 0.5 * sampling frequency) since the
fitted sine wave amplitude is indeterminate.
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Next: Deficiencies Up: Time series processing Prev: Example