CG-FFT for nonuniform inverse fast Fourier transforms (NU-IFFTs)

Based on the CG-FFT method and the NUFFT (nonuniform FFT) algorithm, a new nonuniform inverse FFT (NU-IFFT) algorithm is developed for nonuniform data. With a comparable complexity of O(N log/sub 2/N), this algorithm is much more accurate than the previously reported results since it is optimal in the least squares sense.