global child_path_flag;
y0=input('請輸入玩具的初始位置向量[x y]:');
child_path_flag=input('請輸入兒童行走路線標志值(1.圓；2.正弦曲線；3.橢圓)：');
[t y]=ode45('f',[0 100],y0);
clf;
hold on;
plot(y(:,1),y(:,2),'r');
m=2*pi;
if(child_path_flag==2)
    m=100;
end
t=0:0.05:m;
if(child_path_flag==1)
  [X,Xs,Y,Ys]=child1(t);
elseif(child_path_flag==2)
  [X,Xs,Y,Ys]=child2(t);
else
  [X,Xs,Y,Ys]=child3(t);
end
plot(X,Y,'b:');
a=min(min(y(:,1)),min(X))-1;
b=max(max(y(:,1)),max(X))+1;
c=min(min(y(:,2)),min(Y))-1;
d=max(max(y(:,2)),max(Y))+1;
axis([min(a,c) max(b,d) min(a,c) max(b,d)]);
axis('square');
legend('玩具軌跡','小孩行走軌跡');
title('小孩與玩具');
hold off;