% Coffee Function

function dy = coffee(t,y)
dy = zeros(5,1);
W = 130;    % Body Weight (lbs)
C = 1;      % Norm=1 OralCon=2 Smoking=0.7+/-.2
H = C*(280-W)/26; % Half Life in Hours
S = 6;     % Hours awake
Yo = -abs(S-6)*abs(S-8);
ka = log(2)/H; 
kb = 2.5;
kc = 2.7;
kd = 1/16;
ke = 1.2;
dy(1) = -ka*y(1);    %Half Life Eq. Caf in Body
dy(2) = -kb*y(2)+kc*y(1); % Caffeine in Brain
dy(3) = ke*dy(2)-kd*(S+t-5)^2; % Energy Level
dy(4) = -(1/8)*dy(2)+(1/10)*(S+t-6)^2; % Reaction Time
dy(5) = -(0.8/107)*dy(2)+(1/250)*(S+t-6)^2; % % Errors