% mm2104.mx = (0:.1:1)*2*pi; % same data as earliery = sin(x);pp = spline(x,y); % pp-form fitting rough datappd = mmppder(pp); % pp-form of derivativexi = linspace(0,2*pi); % finer points for interpolationyi = ppval(pp,xi); % evaluate curveyyd = ppval(ppd,xi); % evaluate derivativeplot(x,y,'o',xi,yi,xi,yyd,'--') % plot resultstitle('Figure 21.4: Spline Differentiation')