estimation of parameters using lsqnonlin for system of differential equations

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data
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y = data(:,2);
t = data(:,1);
N = 1390000000;
e0 = 1217378;
a0 = 150;
i0 = 100;
q0 = 30;
h0 = 10;
r0 = 10;
d0 = 0;
s0 = N-e0-a0-i0-q0-h0-r0-d0;
y0 = [s0; e0; a0; i0; q0; h0; r0; d0];
beta0 = 0.5;
alpha0 = 0.004;
gamma0 = 0.1;
upsilon0 = 0.13;
epsilon0= 0.07;
lamda0= 0.1;
sigma0= 0.07;
kappa0= 0.03;
nu0 = 0.0001;
xi0 = 0.0002;
p0 = [beta0; alpha0; gamma0; upsilon0; epsilon0; lamda0; sigma0; kappa0; nu0; xi0 ];
options = optimoptions(@lsqnonlin,'Algorithm','trust-region-reflective');
y = lsqnonlin(Immanuel(t, y, p),y0,[],[],options);
function Immanuel = Immanuel(t, y, p)
% RHS of the ODE
N = 1390000000;
pi = 70000;
zeta = 0.1;
eta = 0.2;
theta = 0.3;
iota = 0.3;
delta = 0.1;
rho = 0.5;
mu = 0.0000425;
beta = p(1);
alpha = p(2);
gamma = p(3);
upsilon = p(4);
epsilon = p(5);
lamda = p(6);
sigma = p(7);
kappa = p(8);
nu = p(9);
xi = p(10);
ydot = zeros(10,1);
S = y(1);
E = y(2);
A = y(3);
I = y(4);
Q = y(5);
H = y(6);
R = y(7);
D = y(8);
ydot(1) = pi -beta*(zeta*A+eta*I+theta*Q+iota*H)*(S/N) -mu*S;
ydot(2) = beta*(zeta*A+eta*I+theta*Q+iota*H)*(S/N) -(delta+mu)*E;
ydot(3) = rho*delta*E-(lamda+gamma+nu+mu)*A;
ydot(4) = (1-rho)*delta*E-(sigma+kappa+mu)*I;
ydot(5) = lamda*A + sigma*I-(alpha+upsilon+mu)*Q;
ydot(6) = alpha*H + kappa*I- (epsilon+xi+mu)*H;
ydot(7) = gamma*A + upsilon*Q + epsilon*H;
ydot(8) = nu*A + xi*H;
end
this code shown error. i dont know how to modify this because i am fresher of matlab
please anyone help me how to find parameters or
please give similar examples on this code
thanks alot sir
  6 Comments
Star Strider
Star Strider on 29 Mar 2022
I only see 8 values for ‘ydot’ although the initial declaration is:
ydot = zeros(10,1);
That could be a problem.
Also, I do not see any call to a differential equation integration function (such as ode45).
Do this search to find examples of how to do this correctly.
.

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