differintP 0.0.4 (Weyl, Riesz)

0.0.4

• Added Weyl and Riesz Fractional Derivative Functions:

  • Weyl: Implements the periodic, right-sided fractional derivative using an FFT-based method. For periodic functions, this operator produces phase-shifted analytical derivatives, and is especially well-suited for spectral methods.
  • Riesz: Implements the symmetric (two-sided) fractional derivative, also using FFT. For pure sines/cosines, the Riesz operator multiplies each Fourier mode by $-|k|^\alpha$, resulting in a real-valued, sign-flipped output (not a phase shift). Especially relevant in physics and PDEs.

• Testing Update:

  • Both Weyl and Riesz are covered by unittest and pytest-style tests for compatibility and reliability.
  • The test suite is transitioned from unittest to pytest for modern, flexible, and more expressive testing.