sigpy.nufft

sigpy.nufft(input, coord, oversamp=1.25, width=4)[source]

Non-uniform Fast Fourier Transform.

Parameters:
  • input (array) – input signal domain array of shape (…, n_{ndim - 1}, …, n_1, n_0), where ndim is specified by coord.shape[-1]. The nufft is applied on the last ndim axes, and looped over the remaining axes.
  • coord (array) – Fourier domain coordinate array of shape (…, ndim). ndim determines the number of dimensions to apply the nufft. coord[…, i] should be scaled to have its range between -n_i // 2, and n_i // 2.
  • oversamp (float) – oversampling factor.
  • width (float) – interpolation kernel full-width in terms of oversampled grid.
Returns:

Fourier domain data of shape

input.shape[:-ndim] + coord.shape[:-1].
Return type:

array

References

Fessler, J. A., & Sutton, B. P. (2003). Nonuniform fast Fourier transforms using min-max interpolation IEEE Transactions on Signal Processing, 51(2), 560-574. Beatty, P. J., Nishimura, D. G., & Pauly, J. M. (2005). Rapid gridding reconstruction with a minimal oversampling ratio. IEEE transactions on medical imaging, 24(6), 799-808.