Change plot size

So I have to make a picture like this

I have a few questions. How can I change the size when plotting. So far I have this:
Screenshot 2022-01-02 172556
It kinda looks like the brows and the mouth but it’s too big. How can I change that?
Also how can I make an ellipse for the head with this equation: x^2+y^2=1?
And lastly how can I make the axis look like in the smiley face picture? As you can see from the second picture my axis look a bit different. Thanks!
This is my code
x = 0:0.1:2*pi;
y = sin(x);
v = [x(: ) y(:)];
pkg load matgeom;
%drawEllipse([3 0.7 3.25 3.5 0]);
for i = 0:0.0555555556:0.5
plot(x, y+i);
%plot(x + 1.5, y+i);
hold on;
grid on;
axis([-0.5 6.5 -4 4.5], “square”);

Hi GasiJeGej

Answering to the question about the proportions of the mouth, you can adjust it with axis, when you are ploting the mouth, you must write something like that:

axis([1.6 4.6 -3 -1]);

This will take the plot closer and with the real dimensions.

Answering to the ellipse, take the ecuation of an ellipse:

(y/a)^2 + (x/b)^2 = 1

If you want a ellipse more depth in x than y, you must take ‘b’ bigger than 1 and ‘a’ as 1.
If you want a ellipse depth in y than x, a must be bigger than 1 and b as 1.

% drawing the ellipse for the face
a = 2;
b = 1;
x = linspace(-5,5,1000);
y = b*sqrt(1 - (x/a).^2); % remember that has positive and negative parts

hold on;
plot(x,-y,'b'); % negative part
axis([-5 5 -5 5]);

Resolving the final question, it is because the axis are not simetric, let me explain, if you put the horizontal axis from -1 to 1 for example, you must set the vertical axis so if you put it from A to B, B - A must be the same as you did in horizontal axis, in this example -1 -(-1) = 2.
In your example, you have to put axis as ``` axis([0 6 -3 3]) for example.

Regards and enjoy experimenting with octave :slight_smile:

Thanks for your answers. I am still a bit confused about the first question. When I put

axis([1.6 4.6 -3 -1]);

when plotting it just zooms in really close but the figure I plotted remains the same size when I zoom out. I kinda understand what you mean but I need to adjust the size of every component of the smiley’s face and I am not sure how to do it with the axis. I am new to octave so maybe it is right but I don’t understand it yet.

You can try with the calibration tools that octave plot has at the top

you can use Z+ and select a part of area and see the axis to take knowledge about how much axis do you need, also you can use Autoscale if you want to reverse your actions, and Z- to move away.