forest.m

林火预测元胞自动机的代码

%
%CA driver
%
%forest fire

clf
clear all

n=100;

Plightning = .000005;
Pgrowth = .01; %.01

z=zeros(n,n);
o=ones(n,n);
veg=z;
sum=z;


imh = image(cat(3,z,veg*.02,z));
set(imh, 'erasemode', 'none')
axis equal
axis tight
 
% burning -> empty
% green -> burning if one neigbor burning or with prob=f (lightning)
% empty -> green with prob=p (growth)
% veg = {empty=0 burning=1 green=2}
for i=1:1000
    %nearby fires?
    
     sum = (veg(1:n,[n 1:n-1])==1) + (veg(1:n,[2:n 1])==1) + ...
           (veg([n 1:n-1], 1:n)==1) + (veg([2:n 1],1:n)==1) ;
 
    veg = ...
         2*(veg==2) - ((veg==2) & (sum>0 | (rand(n,n)<Plightning))) + ...
         2*((veg==0) & rand(n,n)<Pgrowth) ;
     
    set(imh, 'cdata', cat(3,(veg==1),(veg==2),z) )
    drawnow
end