  Non-uniform fast Fourier Transform (NUFFT) and inverse NUFFT (INUFFT)
algorithms, based on the Fast Multipole Method (FMM) are developed and tested.
Our algorithms are based on a novel factorization of the FFT kernel, and are
implemented with attention to data structures and error analysis.
  Note: This unpublished manuscript was available on our web pages and has been
referred to by others in the literature. To provide a proper archival reference
we are placing it on arXiv.
