fft vs nufft- scaling

18 views (last 30 days)
nathan blanc
nathan blanc on 5 Aug 2022
Commented: nathan blanc on 7 Aug 2022
I tried to do a fast fourier transform to a non-uniformly sampled data using nufft. The order of magnitude of the results was weird so I tried to compare the results of MATLAB's fft example. The results seem identical except for a scaling factor of about 550. see attahced script and attached picture of the results from the script.
where does this order of magnitude difference come from? how should I scale the nufft results? It seems pretty obvious that the nufft is the "problematic one" as the magnitude of the fft is approximatly equal to the multiplier (~0.7, 1) in the original signal.
many thanks

Accepted Answer

David Goodmanson
David Goodmanson on 6 Aug 2022
Hi Nathan,
In the fft case you are dividing by N = 1500 and multiplying by 2. For nufft you aren't doing that. Hence the factor of about 750.
nathan blanc
nathan blanc on 7 Aug 2022
Thanks again David

Sign in to comment.

More Answers (0)




Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!