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//This function is for curve fitting using least-square
clear
clc
//The function to be fitted
exec fit_function.sci;
//The error function
exec errorfun.sci;
//Read measured data
Data = csvRead('../Data/Tut3_Data.csv')
//Time stamp
time = Data(:,1);
//Measured output
measured_data = Data(:,2);
// initial parameters guess
initial_condition = [1 ; 1];
//Call least square function,
//Output is function value (func_value_xopt) at optimal coefficients (x_optimal))
[func_value_xopt,coeff_optimal] = leastsq(list(errorfun,time,measured_data),initial_condition)
error = errorfun(coeff_optimal,time,measured_data)
disp(error,'The error after least square approximation')
// Plot of measured data and fitted data versus time
// a small graphic
fit_time = 0:0.01:15;
fitted_data = fit_function(fit_time, coeff_optimal);
plot2d(time, measured_data, -1)
plot2d(fit_time, fitted_data, 2)
legend(["measure points", "fitted curve"],[-1,2],"ur");
xtitle("a simple fit with leastsq","time","data")
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