[SciPy-user] number of function evaluation for leastsq

Bruce Southey bsouthey@gmail....
Wed Apr 16 09:40:15 CDT 2008


Fabrice Silva wrote:
> Le mercredi 16 avril 2008 à 15:32 +0200, Achim Gaedke a écrit :
>   
>> I am testing different physics models whether they comply with the
>> measurement. So I can not optimize each model before testing in detail,
>> I could not even simplify the model, because I want to investigate the
>> contribution of different effects.
>> I am not really terrified by 1.5h for each data point. But I have the
>> opportunity to compare the logs of each run.
>>     
>
> Which language do you use to compute each 1h30 evaluation ? python, C,
> fortran ? If python, it may be worth writing it in fortran and use f2py
> for example...
>   
Hi,
I would also add it would be clearer to know what you want to achieve. 
In part, one reason is that there may be a better way to achieve your 
goal as the model is extremely complex or the data used is inappropriate 
(very badly conditioned). If you are just changing parameters and 
assuming the model is reasonably well behaved, then you should use 
starting values close to the base model. If it is the data then you 
should do something to the data like normalize.

Bruce


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