# Could anyone help me with the interp1 please?

1 view (last 30 days)
Avan Al-Saffar on 25 Nov 2014
I have a system of two equations with two variables,I am using ode45 to solve the system numerically then trying to find Fisher Information(I),,Because my variables x(1) and x(2) depend on time so I am using '' interp1 '' ,,The problem is that I am not sure of using ' interp1' and the second thing I am getting two values for (I) while I am expecting to get only one value!
My code is :
function RunFisherpaperInt
A=1;
x0=[12 5];
dt=0.1;
tspan=0:dt:100;
b=4;
[t,x]=ode45(@Fisherpaper,tspan,x0,[],b);
x=[x(:,1),x(:,2)];
X = @(T) interp1(t,x,T) ;
a1=(15.*X(1)-b.*X(1).*X(2)) ;
b1=(-5.*X(1)+0.5.*X(1).*X(2)) ;
f = @(T) (A.*( (( a1.*( a1.*(15 - b.*X(2)) + b1.*(0.5.*X(2)) ) + b1 .*(a1.*(-b.*X(1)) +b1.*(-5 +
0.5.*X(2)) ) ).^2)./(a1.^2+b1.^2).^3 ) ) ;
I = integral(f,0,100,'ArrayValued',true)
1;
% function dxdt = Fisherpaper(t,x,b)
%x(1) = prey
% x(2) = predator
% dxdt=zeros(2,1);
% dxdt(1) = 15 * x(1) - b * x(1).* x(2);
% dxdt(2) = -5 * x(2) + .5 * x(1).* x(2);
% end