vstupdata=importdata('data.txt');
x=vstupdata(:,1);
y=vstupdata(:,2);
polynom7=polyfit(x,y,7);
plot(x,y,'*');

hold on
xx=linspace(x(1),x(end),100);
yy=polyval(polynom7,xx);
yy=interp1(xx,yy,xx,'spline');
plot(xx,yy,'r');