Why is plot using range of values with increments not proper?

I am a begginer using matlab for college lab. I am trying to experiment with the range with increment operation and I notice some weird output.

When I use greater increment values the output starts becoming wrong but when i use smaller increment values the output become correct. I have attached the code below and their respective outputs for reference

F = 2000;
t = 0.99:0.001:1;
x = sin(2*pi*F*t);
plot(t,x);

In the above code, in the y axis output the values go above the normal sine range [-1,1]

F = 2000;
t = 0.999:0.00001:1;
x = sin(2*pi*F*t);
plot(t,x);

While for this code the output works percectly.

Could anyone please give an insight in this?

Thank you

Answer 1

[DGM]

"In the above code, in the y axis output the values go above the normal sine range [-1,1] "

No they don't. Look at the labels again. All of those values are close to zero. It's just a matter of aliasing. There are only 11 samples.

F = 2000;
t = 0.99:0.001:1;
x = sin(2*pi*F*t);

plot(t,x,'*'); hold on;

% plot the exact same thing with more points
t = linspace(0.99,1,1000);
x = sin(2*pi*F*t);

plot(t,x);

[Laxman Chinnannavar]

Oh, Thanks @DGM, didnt see the 10^(-12) at the side.