The problem is that when you specify a character vector for the function, then the function cannot be a local function (must have it's own .m file)
But you have another problem:
% Parameters of SIRC model
n1=nlmpc(4,4,1);
n1.PredictionHorizon=100;
n1.ControlHorizon=10;
n1.Ts=1;
n1.Model.StateFcn=@sircstatefcn;
n1.Model.OutputFcn=@sircoutput;
S0 = 0.1; % Initial susceptible population
I0 = 0.3; % Initial infected population
R0 = 0.5; % Initial recovered population
C0 = 0.1;
x0 = [S0, I0, R0, C0]; % Initial conditions
u0=0.2;
validateFcns(n1,x0,u0)
function dx = sircstatefcn(x,u,p)
p.mu = 0.015;
p.alpha = 100;
p.delta = 0.625;
p.gamma = 0.30;
p.sigma= 0.1;
p.beta0 = 0.5;
fx=zeros(4,1);
fx(1)=p.mu*(1-x(1)) + p.gamma*x(4);
fx(2)= -(p.mu + p.alpha)*x(2);
fx(3)=p.alpha*x(2) - (p.mu + p.delta)*x(3);
fx(4)=p.delta*x(3) - (p.mu + p.gamma)*x(4);
gx=zeros(4,1);
gx(1)=-x(2)*x(1);
gx(2)=x(2)*x(1) + p.sigma*x(4)*x(2);
gx(3)=(1-p.sigma)*x(2)*x(4);
gx(4)=-x(4)*x(2);
dx=fx+gx*u;
%original state space model
% dx = [ p.mu*(1-x(1)) - u(1)*x(2)*x(1) + p.gamma*x(4);
% u(1)*x(2)*x(1) + p.sigma*u(1)*x(4)*x(2) - (p.mu + p.alpha)*x(2);
% (1-p.sigma)*u(1)*x(2)*x(4) + p.alpha*x(2) - (p.mu + p.delta)*x(3);
% p.delta*x(3) - u(1)*x(4)*x(2) - (p.mu + p.gamma)*x(4)];
dx=dx';
end
function y= sircoutput(x,u)
y(1)=x(1);
y(2)=x(2);
y(3)=x(3);
y(4)=x(4);
y=y';
end
