h4 = 10/4;
h8 = 10/8;
h12 = 10/12;
h16 = 10/16;
% Ekvidistantne - tocke - Cebiseva
x4 = [-5:h4:5];    %x4 = 5*cos(pi*(x4+5)/10)
x8 = [-5:h8:5];    %x8 = 5*cos(pi*(x8+5)/10)
x12 = [-5:h12:5];  %x12 = 5*cos(pi*(x12+5)/10)
x16 = [-5:h16:5];  %x16 = 5*cos(pi*(x16+5)/10)
% Za ekvidistantno aproksimacijo zgostitev na robu
 %x16(2:8)=x16(2:8)-0.5
 %x16(10:16)=x16(10:16)+0.5
xx = [-5:0.01:5];
f4 = 1 ./(1+x4.^2);
f8 = 1 ./(1+x8.^2);
f12 = 1 ./(1+x12.^2);
f16 = 1 ./(1+x16.^2);
ff = 1 ./(1+xx.^2);
p4 = polyfit(x4,f4,4);
p8 = polyfit(x8,f8,8);
p12 = polyfit(x12,f12,12);
p16 = polyfit(x16,f16,16);
figure(1)
%subplot(221)
plot(xx,ff,xx,polyval(p4,xx),'--')
title('n=4')
pause
%subplot(222)
plot(xx,ff,xx,polyval(p8,xx),'--')
title('n=8')
pause
%subplot(224)
plot(xx,ff,xx,polyval(p12,xx),'--')
title('n=12')
pause
%subplot(224)
plot(xx,ff,xx,polyval(p16,xx),'--')
title('n=16')
  max(abs(ff-polyval(p16,xx)))
  figure(2), plot(ff-polyval(p16,xx))