a=0.3;

b=8.7;

n=10;

pol=2;

h=(b-a)/10;

x1=h*(b+a);

x2=0.3*(b-a)+2*h;

f=@(x) (sin(x)+0.5*cos(2*x)+0.5*x);

x = zeros(1,n);

y = zeros(1,n);

for i=1:n

x(i)=a+i*h;

y(i)=f(a+i*h);

end;

for pol_st=1:5

xx=linspace(min(x),max(x),pol);

pol=pol+1;

yy=0;

for i=1:n

P=1;

for k=1:n

if(i~=k)

P=P.*(xx-x(k))./(x(i)-x(k));

%.* - поэлементное умножение

%./ - поэлементное деление

end

end

yy=yy+y(i)*P;

end

plot(xx,yy);

hold on;

end

fplot( '[sin(x)+0.5*cos(2*x)+0.5*x]',[0.3 8.7],0.0001)

plot(x,y,'*r');

grid on

plot(xx,yy,'bo');

%legend('sin(5*x)/x','{\itL_n}({\itx})','nodes',-1)

legend('pol=1','pol=2','pol=3','pol=4','pol=5','sin(x)+0.5*cos(2*x)+0.5*x','nodes:x,y' ,'nodes:xx,yy');