function [ f ] = predator_prey( t, y )
% Function for example 7.8 of the manuscript.

global alpha;
global beta
global gamma
global delta
f = zeros(2,1);
f(1) = alpha * y(1) - beta*y(1)*y(2);
f(2) = -gamma * y(2) + delta*y(1)*y(2);

end

