Animations

Some animation in MATLAB

Description

Some animations in MATLAB
anim.zip contains

  epitrochoid.m epitrochoid animation
  hypotrochoid.m hypotrochoid animation
  cycloid.m cycloid animation
  doublepend2 double pendulum animation
  test8 animation of ball
  spring2mass spring mass system animation
  BZanimation2 Belousov-Zhabotinsky Reaction animation

Acknowledgements

This file inspired Belousov Zhabotinsky Reaction On 2 Manifold.

• Required Products: Image Processing Toolbox; MATLAB
• MATLAB release: MATLAB 7.1.0 (R14SP3)

[Anton Semechko]

Hi Ankur,

your submission inspired this:

http://www.mathworks.com/matlabcentral/fileexchange/38473-belousov-zhabotinsky-reaction-on-2-manifold

[Anton Semechko]

Hi Ankur. I made some changes to your BZanimation script that make it run much faster. Specifically, I vectorized two of the innermost loops using linear indices.

function BZreaction
%BZreaction animation
%Belousov-Zhabotinsky Reaction animation
%This MATLAB code is converted from Processing code available in this link
%http://www.aac.bartlett.ucl.ac.uk/processing/samples/bzr.pdf

%version 2. Corrected the drift of pixels as suggested
% by Jonh.

xres=256; %x resolution
yres=256; %y resolution

a=rand(xres,yres,2);
b=rand(xres,yres,2);
c=rand(xres,yres,2);
p = 1;
q = 2;
img=zeros(xres,yres,3);

mm = mod((1:xres+2)+xres,xres)+1;
nn = mod((1:yres+2)+yres,yres)+1;
[mm,nn]=meshgrid(mm,nn);
idx=sub2ind([yres xres],nn(:),mm(:));
idx=reshape(idx,[yres xres]+2);

figure
for k=1:1000

c_a = zeros(xres,yres);
c_b = zeros(xres,yres);
c_c = zeros(xres,yres);

for m=1:xres
for n=1:yres

idx_temp=idx(m:m+2,:);
idx_temp=idx_temp(:,n:n+2);
idx_temp=idx_temp(:);
if p==2
idx_temp=idx_temp+(xres+0)*(yres+0);
end

c_a(m,n) =c_a(m,n)+ sum(a(idx_temp));
c_b(m,n) =c_b(m,n)+ sum(b(idx_temp));
c_c(m,n) =c_c(m,n)+ sum(c(idx_temp));

end
end

%correction of pixel drift
c_a = circshift(c_a,[2 2]);
c_b = circshift(c_b,[2 2]);
c_c = circshift(c_c,[2 2]);

c_a =c_a/ 9.0;
c_b =c_b/ 9.0;
c_c =c_c/ 9.0;

a(:,:,q) = double(uint8(255*(c_a + c_a .* (c_b - c_c))))/255;
b(:,:,q) = double(uint8(255*(c_b + c_b .* (c_c - c_a))))/255;
c(:,:,q) = double(uint8(255*(c_c + c_c .* (c_a - c_b))))/255;

img(:,:,1)=c(:,:,q);
img(:,:,2)=b(:,:,q);
img(:,:,3)=a(:,:,q);

if p == 1
p = 2; q = 1;
else
p = 1; q = 2;
end

image(uint8(255*hsv2rgb(img)))
axis equal off
drawnow
end

[John Bullinga]

The BZ animation has a drift of two pixels up and left per cycle that may be corrected by adding

c_a = circshift(c_a,[2 2]);
c_b = circshift(c_b,[2 2]);
c_c = circshift(c_c,[2 2]);

before the 'c_a =c_a/ 9.0;' line