Simulate a dot moving in an ellipse

My code asks a user to in put the coordinates of focus 1 and focus 2 of an obrital ellipse. I just need to figure out how to simulate a dot moving around the ellipse drawn.

clc
clear


x1 = input("Give me the x value of sun (focus 1): "); %check ellipse image
y1 = input("Give me the Y value of the sun(focus1): "); %check ellipse image


x2 = input("Give me the x value of focus 2: "); %check ellipse image
y2 = input("Give me the Y value of focus 2: "); %check ellipse image
hold on



hold on
drawellipse(x1,x2,y1,y2)
hold off

Sun(x1,y1,'yellow') 


%% functions
function drawellipse(x1,x2,y1,y2)


% Define parameters.


%set up perihelion (closed to the sun)

Rp = sqrt ((x1)^2 + (y1)^2);

%Set up aphelion (farthest from sun)

Ra = sqrt((x2)^2 + (y2)^2);

%determine eccentricity (how flat or round the shape of the ellipse is) 
%from Rp and Ra
eccentricity = (Ra-Rp)/(Ra+Rp);

numPoints = 500; % Less for a coarser ellipse, more for a finer resolution.
%the larger the number the smoother the ellipse will look

% Make equations:

% a is the distance from the center of the elipse to the (aka length of the
% semi-major axis
a = 0.5 * (Rp + Ra);

% c is the distanc from the center of the elipse to the focii (the sun's
% location is one focus)
c = eccentricity*a;

%length of the semininor axis
b = sqrt(a^2 - c^2);


%creates the empty ellipse
t = linspace(0, 2 * pi, numPoints); %from 0 radians to 2pi radians
X = a * cos(t);
Y = b * sin(t);
% Compute angles relative to (x1, y1). idk what's happening here lol
angles = atan2(y2 - y1, x2 - x1);
x = (x1 + x2) / 2 + X * cos(angles) - Y * sin(angles);
y = (y1 + y2) / 2 + X * sin(angles) + Y * cos(angles);


% Plot the ellipse as a blue curve.
subplot(1, 1, 1);
plot(x,y,'b-', 'LineWidth', 1);	% Plot ellipse
grid on;
axis equal
end


function Sun(s,v,color)
    hold on
    color=color+".";
    plot(s,v,color,'MarkerSize',75);
    hold off
end

Answer 1

[darova]

Use pause()

t = linspace(0,2*pi,20);
x = 5*cos(t);
y = 3*sin(t);
h = plot(5,0,'.r');
line(x,y)
for i = 1:20
    set(h,'xdata',x(i))
    set(h,'ydata',y(i))
    pause(0.5)
end