MATLAB: Errors when using lsqnonlin in new Matlab version

levenbergmarquardtlsqncommonlsqnonlinnonlinear data-fittingOptimization Toolbox

Hello,
A while ago someone gave me some code to solve my statistics problems (including nonlinear data-fitting). I recently upgraded from Matlab R2010b to R2014b, and now I get error messages like the one below. Does anyone know if something important changed to 'lsqnonlin'? I noticed the errors occur when to most irregular datadistributions are fitted.
Thanks in advance, Seppe
Error using levenbergMarquardt (line 16)
Objective function is returning undefined values at initial point. lsqnonlin
cannot continue.
Error in lsqncommon (line 156)
    [xC,FVAL,JACOB,EXITFLAG,OUTPUT,msgData] = ...
Error in lsqnonlin (line 237)
[xCurrent,Resnorm,FVAL,EXITFLAG,OUTPUT,LAMBDA,JACOB] = ...
Error in SKNrandgen (line 95)
        distr_param=lsqnonlin(@SKNfit,distr_param,[],[],OPTIONS,CurrentBootData,n_obs);

Best Answer

The errors you've posted are not originating from lsqnonlin. They are originating from the objective function, SKNfit. It is returning NaNs, or Infs, or something not legal at the initial point. You should forget about lsqnonlin for now and just focus on SKNfit. Check what it is returning at the initial point.
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