Regression splines (parametric) Smoothing splines (nonparametric Basis functions for piecewise continuous models These constraints can be incorporated directly into the basis functions: h1(z)=1,h2(r)=x,hg(x)=(x-51)+,h4(r)=(x-2)+, where()+denotes the positive portion of its argument: Patrick Breheny STA 621:Nonparametric StatisticsIntroduction Regression splines (parametric) Smoothing splines (nonparametric) Basis functions for piecewise continuous models These constraints can be incorporated directly into the basis functions: h1(x) = 1, h2(x) = x, h3(x) = (x − ξ1)+, h4(x) = (x − ξ2)+, where (·)+ denotes the positive portion of its argument: r+ = ( r if r ≥ 0 0 if r < 0 Patrick Breheny STA 621: Nonparametric Statistics