如何在无限极限之间绘制参数函数？

Question

如何用无限极限绘制这些参数函数以使用matlab获得一个圆？

x(t)=2t/(1+t.^2) 
y(t)=(1-t.^2)/(1+t.^2) 

Answer 1

我不知道无限的限制，但

%Construct a vector of t ranging from a very small number to a very large number 
t = -1000:0.1:1000; 

%Create x and y vectors based on your formula (with a couple of extra dots for element wise division) 
x =2*t./(1+t.^2); 
y =(1-t.^2)./(1+t.^2); 

%Just normal plotting now 
plot(x,y) 

给了我一个圆。但是，（0，-1）仍然会有一个小小的差距。