How can I create the MATLAB code for the same result when the result is implemented in Simulink about State-Space equation solving?

I have 1) Input : timeseries Data, 2) State-Space equation parameter(A,B,C,D).

t_P = (0:0.01:10); % Time
P = 95 + 10*sin(2*pi*75/60*t) + 9*sin(4*pi*75/60*t); % time-varying data

y = [t_P;P];
ys = timeseries(y(2:end,:), y(1,:));
save('inputsigPressure', 'ys','-v7.3'); % Making timeseries data for Simulink

%% State-Space equation Parameter(A,B,C,D) 
R = 0.79;
C = 1.22;
r = 0.056;

AA = -(1/R + 1/r)/C;
BB = 1/(r*C);
CC = -1/r;
DD = 1/r;

So, when I solved the state-space equation with Simulink, I was able to get the result.

(Sample Time in From File Block : 0.01 / Initial Condition in Space-State Block : 0)

But I need to create this process(solving State-Space equation in Simulink) to Matlab code.

ic = 0;
tspan = [0 10];
[t,x] = ode45(@(t,x) odefun(t, x, t_P, P), tspan, ic); % solve s
y = CC*x + DD*P'; % result y => error(The array size of x and P is not match.)

function dxdt = odefun(t, x, t_P, P)
R = 0.79;
C = 1.22;
r = 0.056;

AA = -(1/R + 1/r)/C;
BB = 1/(r*C);

P = interp1(t_P,P,t);
dxdt = AA*x + BB*P; % Space-state equation
end

I know that Simulink use ode45 function in order to solving State-Space equation.

I think x can be solved by ode45 function and y can be obtained by the equation(y = C*x+D*u).

But The array size of x and P is not match.

For result, How can I solve this probrem?

Answer 1

[Paul]

Set

tspan = t_P;

for the call to ode45

[Donggue Kim]

I appreciate your help! It is a nice solution.