如何在无限极限之间绘制参数函数？

Question

如何用matlab绘制这些具有无限极限的参数函数来得到一个圆？

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，但是

%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)

给了我一个圆圈。然而，在(0，-1)附近仍然会有一个很小的差距。