Fast Iterative, Field-Corrected MR Reconstruction Code
to accompany paper:
Sutton, Fessler, Noll: Fast, Iterative, Field-Corrected 
Image Reconstruction for MRI.  Submitted to IEEE Trans. 
Med. Im. June 14, 2002.

simul_test.m - Sample script for simulation object and field map
that does slow and fast iterative recons.

/NUFFT - Non-uniform Fast Fourier Transform code based on paper
Fessler and Sutton: Nonuniform fast fourier transforms using 
min-max interpolation.  Accepted for publication, IEEE Trans. 
Sig. Proc., 2002.

qpwls_pcg - Quadratic Penalized Weighted Least Squares script.

@fast_mr - Fast MR object with field map using NUFFT and time segmentation. 

@mridft - Slow MR object using mex file to perform DFT.

ktraj.mat - kspace trajectory for spiral.

ww.mat - density compensation weightings generated using voronoi areas.


note from brad:

For the rect basis functions for object and piecewise linear for field map,
the code I use to do this is in ~bpsutton/Matlab/@mr_wt_z/, use like fast_mr.
This object calls a mex file in ~bpsutton/Cfiles/mvsswtzp.c
Replace ~bpsutton with /n/ir5/u/bpsutton on eecs machines.
Instead of doing a sinc(kx)sinc(ky) for the rect basis functions, it does a
sinc(kx + Xt)sinc(ky+Yt) where X and Y are the slopes in x and y.

