Version=0.2.0 (07/2026)
=============
0) minor updates
- Removed "beta" status
- Added system requirements (Rust/Cargo for Linux) to README
- Updated CRAN badges
1) Concerning knots
- Replaced the variable "knots" by the variable "knot" everywhere to avoid confusion with knots() R build-in function
- changed notation paradigm: variable "knot" refers to knots including ends (replace int_knots in version 1.0.1)
variable "ext_knot" refers to extended knot partition (replace knots in version 1.0.1)
3) Spline Evaluation
-Added case degree=0 which caused problems since some variables (coeff) lose 1 dimension. R automaticaly reduces the dimension of the arrays.
-Rendered the spline container (list of knots, coefficients, degree) callable
-Allowed the call of a spline to pass the spline basis coefficient to accelerate the computations (as well as in the function eval_spline)
4) Add other degree for constrained regression
- quartic splines using Karlin-studen technique for cubic polynomial (monotone) and quadratic polynomial (convex).
- quadratic and linear splines. No major theoretical difficulty.
- Unify all regression functions in a quantile_spline function with selection of the degree as a parameter
