Could anyone help me with the interp1 please?

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