基于Matlab验证椭圆焦点发出光线，经椭圆壁反射，必经过另一焦点。.zip

clc clear close all figure(1) hold on %% 设置图的大小和位置 set(gcf,'position',[200,40,1000,740]); axis equal title('椭圆焦点反射动态图') a=10; b=8; c=(a^2-b^2)^0.5; C1=[-c,0]; C2=[c,0]; axis([-a-2 a+2 -b-2 b+2]) alphy=0:0.01:2*pi; x=a*cos(alphy); y=b*sin(alphy); plot(x,y,'b-','LineWidth',2) plot(-c,0, 'o','markersize', 10,'markerfacecolor','r','MarkerEdgeColor', 'r') plot(c,0, 'o','markersize', 10,'markerfacecolor','r','MarkerEdgeColor', 'r') n=25; beta=linspace(0,2*pi,n); beta(end)=[]; n=n-1; step=0.1; now_p=zeros(n,2); now_p(:,1)=-c; for i=1:n h(i)=plot(now_p(i,1),now_p(i,2), 'o','markersize',5,'markerfacecolor','k','MarkerEdgeColor', 'b'); end while true for i=1:n next_p=[now_p(i,1)+step*cos(beta(i)) now_p(i,2)+step*sin(beta(i))]; if norm(next_p-C1)+norm(next_p-C2)>2*a [Cross_p,fai]=G_fun(now_p(i,:),next_p,a,b,C1,C2,beta(i)); plot([now_p(i,1),Cross_p(1)],[now_p(i,2),Cross_p(2)],'r-') step1=step-norm(now_p(i,:)-Cross_p); beta(i)=fai; next_p=[Cross_p(1)+step1*cos(beta(i)) Cross_p(2)+step1*sin(beta(i))]; plot([next_p(1),Cross_p(1)],[next_p(2),Cross_p(2)],'r-') else plot([now_p(i,1),next_p(1)],[now_p(i,2),next_p(2)],'r-') end now_p(i,:)=next_p; set(h(i),'xdata',next_p(1),'ydata',next_p(2)); end drawnow if norm(now_p(end-1,:)-C2)<step/2 break end end %% qq115075524