load data2

time=trace_x(1,:)'; %first column in data is saved as time
d_data=trace_y(2,:)';%second column in data is saved as experimental displacements
%maxval=max(d_data');
vval = max(d_data);
index=find(d_data==vval);
time=time(index:end,1)-time(index,1); %first column in data is saved as time
d_data=d_data(index:end);
C0=3;
K0=2;
q0=[C0;K0];
[q,cost]=fminsearch(@cost_beam,q0,[],time,d_data);%find optimal parameters

C=q(1);%optimal values for C and K
K=q(2);
x0=[d_data(1) 0]; %initial conditions
[t,x]=ode23(@ode_model,time,x0,[],C,K); %solve the mass-spring dashpot model
d_model=x(:,1);
plot(time,d_data,'--',time, d_model,'r')
legend('experimental data','model displacement')
title('Two-parameter model estimation');
xlabel('time (s)');
ylabel('displacement');