Test Case NUFFT1 and Real Valued Data about tensorflow-nufft

[jmontalt]

Hi @stefanhiemer, what an interesting application! Glad to know you might find it useful.

Unfortunately, NUFFT normalization is not trivial and there is no factor that will guarantee orthonormality in the general case. You may want to have a look at this thread. Briefly, you need to account for the FFT normalization (based on grid shape), but also for the sampling density in non-uniform space. Check out this example. To estimate the density for an arbitrary set of points, you may find this function useful.

As for the real-valued NUFFT, I do not plan to add this functionality myself for the foreseeable future, as the amount of work is not insignificant. That being said, I understand the purpose and would be happy to accept a contribution and maintain the feature.

[jmontalt]

I'm assuming this question has been answered. Feel free to reopen otherwise!