%Deterministic model based on
%Boots, M. and Y. Haraguchi. 1999. The evolution of costly resistance in
%host-parasite systems. Am. Nat. 153: 359-370

%Coded by C. Webb and D. George May 28, 2008
clear
close all


global  a b c q g sigma
%linear case
a= 2; b= 0.012; c= 0; q= 0.003; g= 1; sigma = 0.01;
x0=[0.4];
tspan=[0 2000];

[t,x]=ode23('disease',tspan,x0);

figure(1)
plot(t,x)
title('Dynamics with evolution')
xlabel('Time')
ylabel('Mean trait value')

