Non-uniform FFT

Hello everybody,

I need your help. I have to perform a non-uniform fast fourier transform. I've find the matlab code:

https://www.mathworks.com/matlabcentral/fileexchange/25135-nufft-nfft-usfft

But I can't use it because I don't understand how I can customize with my data. Could you give me some suggestions?

I've attached my data.

In particular my difficulties regarded how to choose: f,knots,N using my data.

Then I've obtained an error:

During my trials when I evaluate this line:

MattOut_T2=iFGG_1d_type2(MattOut_Gauss,knots,Desired_accuracy);

I've obtained this error:

Error using zeros

Size inputs must be integers.

Error in iFGG_1d_type2 (line 140)

F=[zeros(.5*(R-1)*N,1);F;zeros(.5*(R-1)*N,1)];

where

MattOut_Gauss=FGG_1d_type1(data(:),knots,[Nx],Desired_accuracy);

Answer 1

[mingyu xiao]

I think the problem lies in that, the number of input data of FGG_1d_type1 can be even or odd, but the number of input data of iFGG_1d_type2 must be even.