function y=ozone(t,u)
% Decomposition of ozone. 
% Atkins and Jones, first edition, p. 626
% [t,u]=ode_cg1('ozone', [0, 300], [0; 1; .5],.001);

k11=10;
k12=10;
k21=.01;
% k22=.0001;
k22=0;

% k11=1;k12=1;k21=1;

r11=k11*u(3);
r12=k12*u(2)*u(1);
r21=k21*u(1)*u(3);
r22=k22*u(2)^2;

y=zeros(size(u));

y(1)=r11-r12-r21+r22;
y(2)=r11-r12+2*r21-.5*r22;
y(3)=-r11+r12-r21+r22;


