how can i make this animation faster in MATLAB?

r = 1; 
hmax = 28; 
n = 1000;
h = linspace(0,hmax,n);
t = linspace(0,360,n);
k = 0;

pt = 1/6000;

x = zeros(length(h),length(t));
vx = x;
y = x;
vy = y;
a = r+h;
b = r+hmax/2*(cosd(t).^2)+hmax/2;
for i = 1:n
    x(i,:) = a(i)+r.*cosd(t);
    y(i,:) = b(i)+r.*sind(t);
    vx(i,:) = r+r.*cosd(t);
    vy(i,:) = r+h.*sind(t);
end

figure(3)
ball_bounce1= plot(x,y,'c');
axis([-1 31 -1 31])

grid on 
while k < 10 
    if rem(k,2) == 0 
        for i = 1:n
            set(ball_bounce1,'XData',x(i,:),'YData',y(i,:));
            pause(pt)
        end
    end
    if k > 10 
    break
    end
   
end

[Rik]

I'm not sure that is possible. You could replace the pause with drawnow, but that shouldn't meaningfully impact code performance. Seeing your code, I expect only lowering the requirements or increasing hardware will work. Do you need every iteration?

[Jason Robert]

also is there a way you can help me make the code into cos^2 animation

Answer 1

[VBBV]

hmax = 25; % max height
n = 100; % make this value smaller
h = linspace(0,hmax,n);
t = linspace(0,360,n);
k = 0;
pt = 1/6000; % 

...
    
figure(3)
ball_bounce1= plot(x,y,'c','linewidth',3);

Use the values above and try again

[Jason Robert]

i need the n to be 1000. also the hight needs to be 28. the code is meant to the code to make a ball bounce back and forth between to walls. The ball bounces in the form of cos2 (𝜃) where θ goes from 0˚ to 360˚ with a length of 1000. The max height the ball bounces 28 inches from its center. The distance between the two walls is 30 inches. The radius of the ball is 1 inch. The ball will bounce back and forth 20 times

[VBBV]

ok, You can set the

hmax = 28;

But why do you need 1000 ?

The animation worked faster for me when n is changed keeping all others same

[VBBV]

It may be that you are trying to create just circle using 1000 iterations

[Jason Robert]

i need the length of theta to be a 1000.

[Jason Robert]

i think that might be it. if so how can i make the circle using 1000 iteraitons

[VBBV]

Try using while loop inside the while loop instead of for loop. Do you notice any change in animation display?

[Jason Robert]

i tried using a while loop in a while loop. all that did was show me the graph and the ball didn't animate at all

[Jason Robert]

can you show me how you would do a while loop inside a while loop using the code i provided

[VBBV]

Alternative way is to keep n as 1000. But Use a different variable to for loop limit inside the while loop.

%if true
  kk = 100;
While ...
  ...
  for i = 1:kk
    ...
    pause(pt)
  end
end

[Jason Robert]

What do i put in the while loop. U said "while...." what do i put there

[VBBV]

change this line in your program , i think it works for n = 1000 also

figure(3)
ball_bounce1= plot(x(1:500:end),y(1:500:end),'c','linewidth',3);

[VBBV]

You can also use fanimator function for animating circle. See the resource below

https://in.mathworks.com/help/symbolic/fanimator.html

Answer 2

[per isakson]

"[...] to make a ball bounce back and forth between to walls" This is as fast as it gets - I think (with m-code)

%%
x=1;y=1;
ball_bounce1= plot(x,y,'o');
ball_bounce1.MarkerSize = 24;
axis([-1 31 -1 31])
grid on

N = 400;
for jj = 1 : N
    set( ball_bounce1,'XData',jj*30/N, 'YData',jj*30/N );
    drawnow    
end

Answer 3

[CHENG QIAN LAI]

% If you draw x,y ,you will get 1000 Line objects.
% (ball_bounce1=1000 Line obj)
ball_bounce1= plot(x,y,'c');
numel( ball_bounce1 )  

% Set all line objects(ball_bounce1) to same position, this will slow down the program.
set(ball_bounce1,'XData',x(i,:),'YData',y(i,:));

r = 1; 
hmax = 28; 
n = 1000;
h = linspace(0,hmax,n);
t = linspace(0,360,n);
phi = linspace(0,360,50);  % Reduce array elements

k = 0;
pt = 1/6000;
x = zeros(length(h),length(phi));
vx = x;
y = x;
vy = y;
a = r+h;
b = r+hmax/2*(cosd(t).^2)+hmax/2;

x = a'+ r.*cosd(phi);
y = b'+ r.*sind(phi);
%for i = 1:n
    %x(i,:) = a(i)+r.*cosd(phi);
    %y(i,:) = b(i)+r.*sind(phi);
    %vx(i,:) = r+r.*cosd(t);
    %vy(i,:) = r+h.*sind(t);
%end

figure;

ball_bounce1= plot(0,0,'c');  % ball_bounce1 = 1x1 Line
line(a,b);

axis([-1 31 -1 31])
grid on 

step=1;
k=1;
while k < 10
    
    for i = 1:step:n  % You can try step = 2
        set(ball_bounce1,'XData',x(i,:),'YData',y(i,:));
        pause(pt)  % or  drawnow
    end
    k=k+1;
end