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fftshift(data, distance)
fftshift, data, distance
Shifts the data over some distance, using
Fourier interpolation. The shift distances may be fractional. Each
next specified shift distance is applied to the next dimension of
data. If fewer shift distances are specified than there
are dimensions in data, then the shift distances for the
remaining dimensions are assumed equal to zero.
Because Fourier interpolation is used, the shifting is cyclical (i.e., values that shifts out of the array on one side reappear on the other side), and the power spectrum of the shifted data is equal to the power spectrum of the original.
See also: shift