splines – Meta­Post macros for draw­ing cu­bic spline in­ter­polants

This is a small pack­age of macros for cre­at­ing cu­bic spline in­ter­polants in Meta­Post or Meta­font. Given a list of points the macros can pro­duce a closed or a re­laxed spline join­ing them. Given a list of func­tion val­ues y_j at x_j, the re­sult would de­fine the graph of a cu­bic spline in­ter­po­lat­ing func­tion y=f(x), which is ei­ther pe­ri­odic or re­laxed.