Undefined function or variable 'FDE12'. Error in odefunc (line 40) [~,y] = FDE12(@(t,y) ode23(t,y,​eta,p1,rho​,alpha,bet​a,mu,c1,c2​,mu1,p2,mu​_v,a,b,tau​,omega,q), t, y0);

% Parameters

eta = 0.9;

p1 = 0.1;

rho = 0.05;

alpha = 0.5;

beta = 0.2;

mu = 0.02;

c1 = 0.1;

c2 = 0.05;

mu1 = 0.1;

m = 0.4;

p2 = 0.05;

mu_v = 0.05;

a = 0.1;

b = 0.05;

tau = 0.05;

omega = 0.01;

% Fractional order

q = 1.2;

% Time vector

tspan = [0 100];

dt = 0.1;

t = tspan(1):dt:tspan(2);

% Initial conditions

S0 = 0.9;

E0 = 0.1;

I0 = 0.05;

R0 = 0.01;

Sv0 = 0.01;

Iv0 = 0.01;

Pa0 = 0.01;

y0 = [S0 E0 I0 R0 Sv0 Iv0 Pa0];

% FDE12 method

[~,y] = FDE12(@(t,y) odefunc(t,y,eta,p1,rho,alpha,beta,mu,c1,c2,mu1,p2,mu_v,a,b,tau,omega,q), t, y0);

% Plot results

figure

plot(t, y(:,1), t, y(:,2), t, y(:,3), t, y(:,4), t, y(:,5), t, y(:,6), t, y(:,7))

legend('S', 'E', 'I', 'R', 'Sv', 'Iv', 'Pa')

xlabel('Time')

ylabel('Population')

Answer 1

[Torsten]

Did you copy the source code of FDE12 from the file exchange and put it in your working directory ?

https://de.mathworks.com/matlabcentral/fileexchange/32918-predictor-corrector-pece-method-for-fractional-differential-equations?s_tid=answers_rc2-2_p5_MLT&fbclid=IwAR2KFJEq4J8UCZCDu7_qfY0jVFPkKWz7VQvp3YRWg0F3tqhbkQ9wgfr0Jvw