function f = rabfox(t,y)
% Computes y' for the Volterra model.
% y(1) is the number of rabbits at time t.
% y(2) is the number of foxes at time t.
global alpha % interaction constant
t % a print statement, just so we can see how fast
% the progress is, and what stepsize is being used
f(1,1) = 2*y(1) - alpha*y(1)*y(2);
f(2,1) = -y(2) + alpha*y(1)*y(2);