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Dr. Toni Volkmer
Software
Dr. Toni Volkmer 

NFFT

I'm a maintainer and contributor of the NFFT (Nonequispaced fast Fourier transform) software library. The source code is available at the NFFT GitHub repository. Precompiled Octave, MATLAB, and Julia interfaces can be found here.

multilayer-SSL-NFFT-Examples

Code examples for semi-supervised learning using multilayer graphs and NFFT-based fast summation.

For further details, please read
  • Kai Bergermann, Martin Stoll, Toni Volkmer.
    Semi-supervised Learning for Aggregated Multilayer Graphs Using Diffuse Interface Methods and Fast Matrix Vector Products.
    ArXiv e-prints, 2020, arXiv:2007.05239 [math.NA]. (pdf).

Download

multilayer-SSL-NFFT-Examples.tar.gz

SublinearizedCoSaMPv2

The code for all experiments in Section 5 of
  • Bosu Choi, Mark Iwen, Toni Volkmer.
    Sparse Harmonic Transforms II: Best s-Term Approximation Guarantees for Bounded Orthonormal Product Bases in Sublinear-Time.
    ArXiv e-prints, 2019; arXiv:1909.09564 [math.NA]. (pdf).

Download

SublinearizedCoSaMPv2.zip

sparseFFTrandomR1L

sparseFFTr1l is a collection of MATLAB routines for computing the sparse fast Fourier transform based on random rank-1 lattices in a dimension incremental way.

For further details, please read
  • Kämmerer, L., Krahmer, F., Volkmer, T.
    A sample efficient sparse FFT for arbitrary frequency candidate sets in high dimensions.
    ArXiv e-prints, 2020, arXiv:2006.13053 [math.NA]. (pdf).

Download

sparseFFTrandomR1L-0.1.0.tar.gz is the first version of the software.

sparseFFTr1l

sparseFFTr1l is a collection of MATLAB routines for computing the sparse fast Fourier transform based on reconstructing rank-1 lattices in a dimension incremental way.

For further details, please read
  • Potts, D., Volkmer, T.
    Sparse high-dimensional FFT based on rank-1 lattice sampling.
    Appl. Comput. Harm. Anal. 41, 713 – 748, 2016. (pdf, DOI).

Download

sparseFFTr1l-0.1.5.tar.gz is the updated version of the software with bugfixes and Octave support.

prony_sparseFFT_iterative

prony_sparseFFT_iterative is a collection of MATLAB routines for computing the sparse fast Fourier transform in an iterative way based on Prony's method via MUSIC or ESPRIT. There exists a one-dimensional version as well as a multi-dimensional version based on rank-1 lattice techniques.

For further details, please read
  • Potts, D., Tasche, M., Volkmer, T.
    Efficient spectral estimation by MUSIC and ESPRIT with application to sparse FFT.
    Front. Appl. Math. Stat. 2, 2016. (pdf, DOI).

Download

prony_sparseFFT_iterative-0.1.0.tar.gz is the first version of the software.

nonperiodicR1L

nonperiodicR1L is a collection of MATLAB routines for computing Chebyshev coefficients based on samples along reconstructing rank-1 Chebyshev lattices.

For further details, please read
  • Potts, D., Volkmer, T.
    Fast and exact reconstruction of arbitrary multivariate algebraic polynomials in Chebyshev form.
    Proceedings of the 11th International Conference on Sampling Theory and Applications, 392–396, 2015. (pdf, DOI).
  • Potts, D., Volkmer, T.
    Sparse high-dimensional FFT based on rank-1 lattice sampling.
    Appl. Comput. Harm. Anal. 41, 713 – 748, 2016. (pdf, DOI).

Download

nonperiodicR1L-0.1.1.tar.gz is the updated version of the software with minor bugfixes.

taylorR1Lnfft

taylorR1Lnfft is a collection of MATLAB routines for computing approximated Fourier coefficients based on samples along perturbed nodes of reconstructing rank-1 lattices.

For further details, please read
  • Volkmer, T.
    Taylor and rank-1 lattice based nonequispaced fast Fourier transform.
    In 10th international conference on Sampling Theory and Applications (SampTA 2013), pages 576–579, Bremen, Germany, July 2013. (pdf).
  • Kämmerer, L., Potts, D., Volkmer, T.
    Approximation of multivariate periodic functions by trigonometric polynomials based on rank-1 lattice sampling.
    J. Complexity 31, 543–576, 2015. (pdf).

Download

taylorR1Lnfft-0.1.1.tar.gz is the updated version of the software with minor bugfixes.