Hello Khadak,
To create a spherical indicatrix, you can follow the code below
t = linspace(0, 2*pi, 1000);
a = 1;
x = a * cos(t);
y = a * sin(2*t) / 2;
% Project onto a sphere
z = sqrt(1 - x.^2 - y.^2);
% Plot the sphere
figure;
[xs, ys, zs] = sphere(30); % Create a sphere
mesh(xs, ys, zs, 'FaceAlpha', 1, 'EdgeColor', 'k'); % Plot the sphere
hold on;
% Plot the infinity symbol on the sphere
plot3(x, y, z, 'r', 'LineWidth', 2);
axis equal;
xlabel('X');
ylabel('Y');
zlabel('Z');
grid on;
hold off;
This produces the following output
