Documentation

Rotates the FFT output data array. This function rotates the two sided power spectrum or fourier series generated by fftToPs if the timeseries data is of type DATA_COMPLEX so that the most negative -ve frequency (the nyquist frequency) is the first bin and the most positive (one below the nyquist frequency) frequency is the last bin. This rotation can be done for both power spectra and ffts themselves, depending on the value of the flag data_type. output should be allocated the same amount of memory space as the input array.

Returns:

s 0 if successful, -1 if error

Parameters:

data_length - the number of bins in the power spectrum or fft.
data_type - DATA_REAL (a power spectrum) or DATA_COMPLEX (an fft)
input - a pointer to the input array
output - a pointer to the output array

Author:

Edward Daw, June 1999