Hello everyone,
i am using lsqcurvefit for fitting some data i have. The code i wrote is the following:
[x, resnorm, residual, exitflag, output] = lsqcurvefit(@(x,xdata)myfun(x,xdata,E_x,Gamma_X,Gamma_C), x0, xdata, ydata, lb, ub, options);with given x0, E_x, Gamma_X, Gamma_C, lb and ub. The function myfun is in an another file called myfun.m. The fit works fine but I noticed that the result depends on the choice of the initial guess x0. So i tried to implement a multistart. The code i tried to write based on the examples on the help page is the following:
problem = createOptimProblem('lsqcurvefit','x0',x0,'objective',@myfun,'xdata',xdata,'ydata',ydata);ms = MultiStart('PlotFcns',@gsplotbestf);[xmulti,errormulti] = run(ms,problem,50)This code does not work, it gives me the following error:
Error in myfun (line 9)
F(1,:) = real((E_c + E_x – j*(Gamma_X – Gamma_C))/2 + 1/2*sqrt((E_c – E_x – j*(Gamma_X – Gamma_C)).^2 + 4*par(2).^2));
Error in lsqcurvefit (line 202)
initVals.F = feval(funfcn_x_xdata{3},xCurrent,XDATA,varargin{:});
Error in fmultistart
Error in MultiStart/run (line 260)
fmultistart(problem,startPointSets,msoptions);
Error in CHO_matlab (line 91)
[xmulti,errormulti] = run(ms,problem,50)
Caused by:
Failure in initial objective function evaluation. LSQCURVEFIT cannot continue.
Failure in call to the local solver with supplied problem structure.
My understanding is that the function myfun within problem is missing the inputs parameters. Maybe there is also some other mistake which i do not know. So i replaced @myfun with @myfun(x,xdata,E_x,Gamma_X,Gamma_C) but now i get this error:
Unbalanced or unexpected parenthesis or bracket.
I also tried other similar combinations but noone seems to be acceptable.
What can i do it to make it work? How should i call the function with all the needed parameters?
Thank you all
Best Answer