The Matlab code in this folder implements 1D-3D NUFFTs via fast Gaussian gridding. The convolution loops are written as C programs to be compiled as mex files from the Matlab command prompt. Further mathematical details about the code can be found in L. Greengard and J. Lee, "Accelerating the Nonuniform Fast Fourier Transform," SIAM Review, Vol. 46, No. 3, pp. 443-454.
I have included three example scripts (fgg_1D_experiment.m, etc)that create a simple 1D/2D/3D image and compare the DFT with the Type-I NUFFT (DFT from nonuniform data to uniform image grid). The image data are transformed back to the data domain via the adjoint operator (a Type-II NUFFT--uniform grid DFTed to nonuniform data locations--implemented with IFFTs instead of FFTs) and back again to the image domain to demonstrate the numerical accuracy. This code does not include Type-III transforms (nonuniform-->nonuniform), but one could easily be developed by combining the Type-I and Type-II functions provided here.
Before running any of the test scripts, remember to compile the mex files in the Matlab terminal by executing these commands:
If you publish anything that uses this code, we ask that you please reference the source, as this will encourage future funding for more free Air Force Research Laboratory (AFRL) products. This code was developed through the Air Force Office of Scientific Research (AFOSR) Lab Task "Moving-Target Radar Feature Extraction."
Project Manager: Arje Nachman
Principal Investigator: Matthew Ferrara
But it is a pity that the type-3 is absent!
But there are some problems left to fix
hi,i have problems with the 1D example,i cant get the right reslut.
F = FGG_1d_type1(f,knots,N,accuracy,GridListx)
the input data is nonuniformly-spaced frequency data?????!!!!
@David Craig, replace "//" C++-style comments in the offending files with "/* ... */" comments.
Hi, I am having trouble compiling two of the .c files,
give the following error,
>> mex FGG_Convolution1D_type2.c
Warning: You are using gcc version "4.6.3-1ubuntu5)". The version
currently supported with MEX is "4.3.4".
For a list of currently supported compilers see:
FGG_Convolution1D_type2.c: In function ‘mexFunction’:
FGG_Convolution1D_type2.c:67:16: warning: assignment discards ‘const’ qualifier from pointer target type [enabled by default]
FGG_Convolution1D_type2.c:69:16: warning: assignment discards ‘const’ qualifier from pointer target type [enabled by default]
FGG_Convolution1D_type2.c:71:16: warning: assignment discards ‘const’ qualifier from pointer target type [enabled by default]
FGG_Convolution1D_type2.c:72:5: error: expected expression before ‘/’ token
FGG_Convolution1D_type2.c:75:18: warning: assignment discards ‘const’ qualifier from pointer target type [enabled by default]
mex: compile of ' "FGG_Convolution1D_type2.c"' failed.
??? Error using ==> mex at 208
Unable to complete successfully.
Anyone seen this before,
should have mentioned I use MATLAB Version 220.127.116.115 (R2011a) on ubuntu 12.04
I tried getting the 1D example (forward and adjoint operators) to work with non-uniform samples and, after editing the Matlab function, got the forward transform half-way working before I gave up. The algorithm, used as instructed by the documentation, does not produce correct results as is. (Correctness is in comparison with the direct computation of the non-uniform DFT.)
This doesn't work for 3D non-Cartesian MRI k-space trajectory.
Could you please clarify which routine goes from non-uniform spatial grid to uniform spatial grid? Thanks for the submission.
fix some C files please
Need to properly close the comments:
/ * Copy input pointer Scales_point
/ * Copy input pointer Scales_point * /
In your code you said on request you can submit the code by Liu, can you submit it .....it will be good for comparision and study purpose
Its not working for me, worked for some one or not
Matthew, you are not a "Principle Investigator" unless you investigate principles. You should spell that "principal".
This is a very interesting submission, I'm going to give a look. Thanks!
Bug was fixed in 2D code. Grammatical error fixed in notes (thanks, Cris).
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