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Feature Wishlist

Open NAThompson opened this issue 5 years ago • 11 comments

  • Modified Clenshaw recurrence for all special functions governed by 3-term recurrence relations.
  • Higher dimensional interpolation (Akima has a natural generalization to higher dimensions, but there's some work on getting the API correct.)
  • Prolate spheroidal wavefunctions
  • Higher dimensional quadrature; sparse grids for medium dimensionality, extensions of Gaussian quadrature in lower dimensions.
  • Wavelet transforms, shearlets
  • Bivariate interpolation and quadrature at the Padua points

What else is a natural fit for the library, and is useful?

NAThompson avatar Jan 13 '20 17:01 NAThompson

What else is a natural fit for the library, and is useful?

  • Make further progress on zeta, phi and friends (Lerch phi transcendent, polylog, and more).
  • Extend constants to higher precision such as 10,000 decimal digits and get them tested.
  • Evaluate recent progress in the literature on Bernoulli number generation (can we save memory and/or time compared with extracting Bn from tangent numbers?).

ckormanyos avatar Jan 13 '20 18:01 ckormanyos

What else is a natural fit for the library, and is useful?

  • Legendre functions and associated Legendre functions of arbitrary (non-integer real) order and degree.
  • More special functions of complex argument, particularly on the unit disk. Gamma should be a reasonable place to start. Perhaps complex orthogonal polynomials if these are calculated from straightforward recursion.
  • FFT

ckormanyos avatar Jan 13 '20 19:01 ckormanyos

Friends, if you don't mind, I'm going to clean up this thread since it kinda got off topic and many of the off-topic issues have been resolved.

NAThompson avatar Jan 19 '20 16:01 NAThompson

  • fixed sized polynomials without allocation
  • corresponding polynomial solvers, e.g. analytic, bairstow, companion matrix

octopus-prime avatar Jan 19 '20 18:01 octopus-prime

@octopus-prime : Yup. Also that reminds me: Jenkins-Traub.

NAThompson avatar Jan 19 '20 18:01 NAThompson

Did you notice recent discussion about FFT in mailing list? I think it would be great if math supported FFT for all multiprecision types, especially quad-double, which is currently in the works. And please note that it's not possible to use libfftw as a backend for quad-double.

cosurgi avatar Feb 06 '20 22:02 cosurgi

first and second derivative for interpolations (exist sometimes) 2d interpolation

sebweb3r avatar Feb 07 '20 12:02 sebweb3r

I think every interpolator has the first derivative implemented. Second derivatives of the quintic B-spline are implemented. Other interpolators have the wrong spectral properties and perform poorly on second derivatives.

2D interpolation is coming! (Akima + pchip)

NAThompson avatar Feb 07 '20 13:02 NAThompson

@cosurgi : Totally agree it would be useful, but I really like FFTW and it satisfies all my needs, so other things are a higher priority. I don't know who has the skillset to take on such a difficult task . . .

NAThompson avatar Feb 07 '20 13:02 NAThompson

What else is a natural fit for the library, and is useful?

  • Dirichlet Distribution #317

mrityunjay-tripathi avatar Feb 24 '20 16:02 mrityunjay-tripathi

From discussion with the SciPy Maintainers:

  • Symplectic ODE solver https://github.com/scipy/scipy/issues/12690
  • logcdf for statistical distributions #946
  • entropy for statistical distributions
  • Add support for complex arguments to appropriate statistical distributions
  • Make develop branch work with Scipy https://github.com/scipy/scipy/pull/17432

mborland avatar Jan 24 '23 17:01 mborland