龙格现象.txt

数值计算方法 龙格现象+解决（切比雪夫点的定义）

x3=-1:0.001:1;
y3=1./(1+25*x3.^2);
plot(x3,y3,'-k');
hold on;


n=[2 4 8 10];
for m=1:4
x=-1:0.001:1;
for k=1:2001
L(k)=0;
for i=1:n(m)+1
 x1(i)=-1+2*(i-1)/n(m);
end
for i=1:n(m)+1
 x1(i)=-1+2*(i-1)/n(m);
 l(i)=1;
 for j=1:n(m)+1
  if i~=j
    l(i)=l(i)*(x(k)-x1(j))/(x1(i)-x1(j));
  else
    l(i)=l(i);
  end;
 end;
L(k)=L(k)+l(i)/(1+25*x1(i)*x1(i));
end;
end;
plot(x,L);
hold on;
end;