Hi Erik,
The two data sets would be different. It is true that smoothing
(convolution) in the time domain corresponds to pointwise multiplication
(windowing) in the frequency domain. However, the window that you use
in the frequency domain must be the Fourier transform of the time domain
filter.
The nice thing about a Gaussian is that its Fourier transform is also a
Gaussian (though not the same Gaussian:
http://www.cmrr.umn.edu/stimulate/frame/fwhm/img5.gif).
If you use a cutoff in the frequency domain (a rectangular window) this
corresponds to a convolving with a sinc function in the time domain.
Best wishes
Alle Meije
Erik Chang wrote:
> Hi all,
>
> is it possible that spatial smoothing results in different smoothed dataset
> when conducted in the spatial domain and in the frequency domain (made
> equivalent by setting cut-off freq = 1/FWHM)?
>
> erik
>
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