Known Issues

One should also check the github issues for the project page, https://github.com/flatironinstitute/finufft/issues

Also see notes in the TODO file.

Issues with library

  • When requested accuracy is 1e-14 or less, it is sometimes not possible to match this, especially when there are a large number of input and/or output points. This is believed to be unavoidable round-off error.
  • Currently in Mac OSX, make lib fails to make the shared object library (.so).
  • The timing of the first FFTW call is complicated, depending on whether FFTW_ESTIMATE (the default) or FFTW_MEASURE is used. Such issues are known, and discussed in other documentation, eg https://pythonhosted.org/poppy/fft_optimization.html . We would like to find a way of pre-storing some Intel-specific FFTW plans (as MATLAB does) to avoid the large FFTW planning times.
  • Currently, a single library name is used for single- and multi-threaded versions. Thus, i) you need to make clean before changing such make options, and ii) if you wish to maintain multiple such versions you need to move them around and maintain them yourself, eg by duplicating the directory.
  • The overhead for small problem sizes (<10000 data points) is too high, due to things such as the delay in FFTW looking up pre-stored wisdom. A unified advanced interface with a plan stage is in the works.

Issues with interfaces

  • MATLAB, octave and python cannot exceed input or output data sizes of 2^31.
  • MATLAB, octave and python interfaces do not handle single precision.
  • Fortran interface does not allow control of options, nor data sizes exceeding 2^31.

Bug reports

If you think you have found a bug, please file an issue on the github project page, https://github.com/flatironinstitute/finufft/issues . Include a minimal code which reproduces the bug, along with details about your machine, operating system, compiler, and version of FINUFFT.

You may also contact Alex Barnett (abarnett at-sign flatironinstitute.org) with FINUFFT in the subject line.