Using dde23 with events option

Can someone kindly check this code for me?

I can't seem to find my error. I can't plot the graph because my dimensions are unequal.

%Solving and plotting Model 3

xfinal = 60; %will vary

xRange = [0,xfinal];

y0=[0.005; 1-0.005; 0];%the initial conditions for I,S and R respectively

%I=y(1);

%S=y(2);

%R=y(3);

options = ddeset('Events',@myEventsFcn);

sol = dde23(@challenge213,4,@ddex1hist,xRange,options)

plot(sol.x,sol.y(:,1),'k')

hold on

plot(sol.x,sol.y(:,2),'b')

hold on

plot(sol.x,sol.y(:,3),'r')

xlabel('Days')

ylabel('Population')

xlim([-inf xfinal])

ylim([0 inf])

legend('Infected', 'Susceptible', 'Recovered')

title('Solution to Ordinary Differential Equation Model 3')

function h = ddex1hist(x)

h = [0;1;0];

end

function dydx = challenge213(x,y,Z)

k = 4;

m = 0.8;

ylag1 = Z(:,1);

%ylag2 = Z(:,2);

dydx = [m*y(1)*y(2) - m*ylag1(1)*ylag1(2); -m*y(1)*y(2); m*ylag1(1)*ylag1(2)];

end

function [position,isterminal,direction] = myEventsFcn(x,y,Z)

position = [y(1)-(10^-5); y(2)-(10^-5); y(3)]; % the function I is unknown

isterminal = [1; 1; 1]; %terminate when I(t) drops below 10^-5

direction = [0; 0; 0];

end

thank you

Answer 1

[Torsten]

plot(sol.x,sol.y(1,:),'k')
hold on
plot(sol.x,sol.y(2,:),'b')
hold on
plot(sol.x,sol.y(3,:),'r')

[SA]

It worked. Thank you Torsten.