MATLAB: Problems with lsqcurvefit

lsqcurvefit

In trying to fit 3 parameters in an ODE system using lsqcurvefit, but MATLAB gives me the following error message:

??? Error using ==> lsqcurvefit at 253
Function value and YDATA sizes are incommensurate.
Error in ==> fit_massb at 21
[kfinal,resn,error,exf,out,l,jac]=lsqcurvefit(@callmassb,k0,tspan,yd,lb,ub,[],x0);

What does this mean?

Best Answer

See Why do I receive an error message when using LSQCURVEFIT in the Optimization Toolbox?

Related Solutions

MATLAB: Simultaneous curve fitting using “fmincon”

This is because you have GradObj On but your function does not provide gradient vector.

Try something like this:

options = optimset('Display','iter','MaxFunevals',4000,'TolFun',1e-10 ,'Algorithm','interior-point');
fitfunc = @(c)fitfunction(c,y30,y60);
 parameter =fmincon(fitfunc,x0,[],[],[],[],lb,ub,nonlcon,options);

MATLAB: Problem with nonlinear curve fitting – lsqcurvefit

Hi Alex, this link may help you get started:

http://www.mathworks.com/help/matlab/math/example-curve-fitting-via-optimization.html

Using optimization routines in MATLAB are very similar across functions. The idea in fitting a curve is to set up an error function usually sum of squared errors, and ask the optimization tool (your choice) to minimize it.

x = patternsearch(@err,x0)

Best Answer

Related Solutions

MATLAB: Simultaneous curve fitting using “fmincon”

MATLAB: Problem with nonlinear curve fitting – lsqcurvefit

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