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Changelog

Source: NEWS.md

zufft 0.1.0

First release.

  • fft_c2c(), fft_r2c() and fft_c2r() compute complex, real-to-complex and complex-to-real discrete Fourier transforms over any axes of an array, with SciPy’s crop-or-pad n and norm = "backward", "ortho", "forward" or "none" (the unnormalised convention of fftwtools and stats::fft()).
  • With axes = NULL, fft_r2c() and fft_c2r() halve the first dimension, the contiguous one in R, as fftwtools’ 2-D and 3-D real transforms do; give axes explicitly to halve the last axis listed, as SciPy does.
  • Results are bit-identical whatever the number of threads: zufft_info()$fp_contract is "off" for every build that cannot fuse multiply-adds, which includes all of CRAN’s.
  • fft_dct() and fft_dst() compute discrete cosine and sine transforms of types 1 to 4 and their inverses over any axes, with SciPy’s definitions, norm and orthogonalize.
  • fft_next_len() and fft_prev_len() find fast transform lengths; fft_freq(), fft_rfreq(), fft_shift() and fft_ishift() are SciPy’s frequency and shift helpers.
  • fft_stats() and mvfft_stats() are drop-in replacements for stats::fft() and stats::mvfft().
  • workers runs a transform on several threads, through zufft’s own lazy thread pool; fft_workers(), with_fft_workers() and local_fft_workers() set the default. Results do not depend on the number of threads, and forked children (parallel::mclapply()) are safe.
  • A registered C table and the header inst/include/zufft.h let other packages call the transforms from C with LinkingTo: zufft, from any thread.
  • Setting the environment variable ZUFFT_CXXFLAGS (for example to "-march=native") before installing from source builds zufft for the local CPU on Linux and macOS; see the README.
  • vignette("migrating-from-fftwtools") maps every fftwtools function to zufft; an article covers scipy.fft users.
  • Bundles the BSD-licensed FFT subset of ducc0 (the files and commit SciPy vendors) and compiles it.
  • zufft_info() reports the vendored ducc0 and SciPy commits, the SIMD backend and width, fused multiply-add support, the threading mode and the complex path.