Re: [Bug-gsl] gsl_multifit_fsolver

[Patrick Alken]

The pointer T_ needs to be initialized prior to the alloc call. However, 
according to the manual, there are currently no algorithms implemented 
without derivatives. One option you have is to use fdfsolver with a 
finite difference Jacobian. See the example in the manual for how to do 
this.

Patrick

On 06/03/2015 11:11 AM, Patrick Dupre wrote:
> Hello,
>
> I am trying to use:
> #include <gsl/gsl_multifit_nlin.h>
>
> But this simple exmpale just this makes it fails:
>
> int main () {
>    const gsl_multifit_fsolver_type *T_ ;
>    gsl_multifit_fsolver *s_ ;
> //  T_ = (gsl_multifit_fsolver_type*) malloc (300 * sizeof 
> (gsl_multifit_fsolver_type)) ;
>    s_ = gsl_multifit_fsolver_alloc (T_, 1, 1);
>    }
>
> It seem that it is an issue with the allocation of the gsl_multifit_fsolver_type
> I cannot find any example.
>
> Things works better with gsl_multifit_fdfsolver_type
> but this requires to setup the derivatives that I cannot do it because
> my function is a complex.
>
> Do you know who could provide me some help?
>
> Thank for your help.
>
> ===========================================================================
>   Patrick DUPRÉ                                 | | email: address@hidden
>   Laboratoire de Physico-Chimie de l'Atmosphère | |
>   Université du Littoral-Côte d'Opale           | |
>   Tel.  (33)-(0)3 28 23 76 12                   | | Fax: 03 28 65 82 44
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