function y=recfun(b) 


global data; 

x=data(:,1); 
y_soll=data(:,2); 

simulation(b);

   % the calculated value from the model 
 
pause(0.25);

data_m=xlsread('data_m.xlsx');


y=data_m(:,1)-y_soll; 

% y_roh=y_ist-y_soll; 
% y=sum((y_roh).^2);
% 
% h=figure;

plot(x,data_m(:,1),'r',x,y_soll,'b');
hold on;
% close(h);
%y=sum((Rcal-Rexp).^2);