function v = logdist(t, Y, Z, a)
v = zeros(2,1);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
x = Y(1);
y = Y(2);
ylag = Z(:,1);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
dxdt = y-ylag(2);
dydt = a*y*(1-x);
v = [dxdt; dydt];