Piecewise: Piecewise, Mathematics, Function (mathematics), Independent Variable, Subderivative, Convex Analysis, Absolute Value

Smoothing Spline: Smoothing, Spline Function, Spline, Mathematics, Piecewise

Segmented Regression: Regression Analysis, Independent Variable, Piecewise Linear Regression, Dependent Variable

Convex function: function, Mathematics, Function (mathematics), Subset, Interval (mathematics)

Tropical Geometry: Mathematics, Piecewise Linear Manifold, Algebraic Geometry