`contrib.sympy`

[jorenham]

Optional support for SymPy, e.g. utility functions for:

• extend the sympy.stats distributions with symbolic L-moment methods, analogously to scipy.stats
• finding closed-form solutions of theoretical
  • order stats
  • PWM's
  • L-moments
  • L-comoments
  • L-moment (asymptotic) variance-covariance matrix
  • IF's, BP's, etc.
  • L-MGF's 😏
• allow using sympy's numerical integration as an alternative to the current scipy.integrate.quad
• support for using the interpolative summation method in l_poly (as alternative to the current naïve summation)
• Hahn polynomials (use $_3F_2$; it's absent in scipy), which show up in the trimmed L-moment weights (Hosking, 2015).