a = -1; b = 1;
xmany = linspace(a,b,500);
for n = 2:2:30,
    x = linspace(a,b,n+1);
    y = 1./(1+25*x.^2);
    ymany = 1./(1+25*xmany.^2);
    y1 = -2/(1+(-5)^2)^2*(-5);
    yn = -2/(1+(5)^2)^2*(5);
    p = spline(x,[y1,y,yn],xmany);
    
    subplot(2,1,1);
    plot(xmany,ymany,'b-',xmany,p,'r-');
    makelarge
    title(sprintf('Vollst. Spline, n = %i',n));
 
    subplot(2,1,2);
    semilogy(xmany,abs(ymany-p),'r-');
    makelarge
    title('Interpolationsfehler');
    pause
end