This code has many dependencies, where copyrights are described in
their respective packages.

Intenrally the folloiwng copyrights are held:

* Sylvan Elhay, Jaroslav Kautsky. John Burkardt for their Gauss 
  quadrature routines which is released under the GPL licence

* The copyright is for the slice sampling algorihm is held by the
  nlmixr team.  However, we the algorithm is described by Neal,
  RM. <https://projecteuclid.org/download/pdf_1/euclid.aos/1056562461>

* Emmanuelle Comets, Audrey Lavenu, Marc Lavielle for SAEM algorithm
  and their SAEMIX package, which was released under the GPL.  The
  code in this routine is written by Wenping Wang and relased under the GPL

* The Laboratory of Applied Pharmacokinetics and Bioinformatics (LAPKB)
  for the Pmetrics engine and its Rust crates pmcore and pharmsol, both
  released under GPL-3.  The nonparametric estimation code in this package
  (the NPAG / NPB engines: Burke's interior-point weight solver in
  src/npCommon.cpp, and the adaptive-grid / condensation routines) is a
  C++ reimplementation derived from those crates and is released under the
  GPL.  See <https://github.com/LAPKB/PMcore> and the algorithm papers by
  Yamada et al. (2021) and Tatarinova et al. (2013).

The code is distributed under the GPL version 2 or greater.
