[proFit-list] Pro Fit and Applescript

[pro Fit Support]

That's correct. The LM method needs to take derivatives and invert 
matrices, things that can be sensitive to initial conditions. The 
"Robust" methods tries to follow a landscape to find a minimum by 
sensing the environment.

This offers choice and control: If you get singularities in LM it is 
because your initial guesses for the parameters are too far away, or 
because two parameters have similar effects on the function (or are 
redundant).

In such a case, you can change the initial guess by hand, or you can 
use the Robust algorithm to improve the guess.

The Robust algorithm will quickly deliver a better fit which can then 
be used as a starting point for the LM algorithm (LM is faster).

Most often than not, the Robust algorithm may even already take you 
directly to the best fit.

In any case, run the LM algorithm at the end, so that you can get 
more statistical information on the fit (things like parameter 
errors, etc.)

ivan

>Usually, when the LM algorithm gives a singularity, the robust 
>method works. As far as I understand it, the robust method is for 
>that purpose.
>
>Cheers
>Chris
>
>On Aug 22, 2009, at 10:20 AM, Nic Meyer wrote:
>
>>thanks to everyone for their replies.
>>
>>I have been trying the recording option and it sure helps.
>>
>>that said, I am running into problems  of singularities when 
>>fitting my curves (which IGOR handles without complaint) so that is 
>>a new hurdle to overcome (in particular i am trying to fit 
>>lognormal curves and am wondering whether I should specify my own 
>>function for this)
>>
>>given that i do need results soon i will take them from IGOR, but 
>>as a Mac user i am happy that their could well be a possibility 
>>where everything could be scripted.
>>
>>cheers
>>
>>Nic
>>
>>
>>
>>
>>From: pro Fit Support <<mailto:profit at quansoft.com>profit at quansoft.com>
>>To: all things about pro Fit 
>><<mailto:profit-list at quantum-soft.com>profit-list at quantum-soft.com>
>>Sent: Friday, August 21, 2009 5:37:44 PM
>>Subject: Re: [proFit-list] Pro Fit and Applescript
>>
>>In addition to the comments provided by Chris and Davide:
>>
>>One way to learn about controlling pro Fit through AppleScript or a 
>>Pascal script is by exploiting the fact that pro Fit is 
>>"recordable": When you hit the "record" button in AppleScript 
>>Editor or one of pro Fit's function windows, and then execute some 
>>commands manually within pro Fit (such as fitting a function, or 
>>binning data), most of these operations will be recorded as Apple 
>>Script or Pascal statements for you. This usually gives a good 
>>starting point for writing a script. Give it a try.
>>
>>
>>Best regards
>>
>>Kurt Sutter
>>QuantumSoft
>>
>>
>>On 21 Aug 2009, at 7:43, Nic Meyer wrote:
>>
>>>Good morning,
>>>
>>>I found Pro Fit yesterday and am really impressed that this useful 
>>>tool could be completely controlled via applescript. (which I am 
>>>already using extensively). I am trialling Profit for scientific 
>>>data analysis and curve fitting and the program compares well with 
>>>equivalent packages but with the added bonus of (apparently) being 
>>>fully scriptable
>>>
>>>That said, very few examples exist showing the manner in which one 
>>>can script ProFit. In particular I am looking to run Levenburg 
>>>fits and would also like to test the bin data functionality. I 
>>>would also like to be able to perform calculations on the fit 
>>>curves which are generated.
>>>
>>>
>>>I have access to the Pro Fit dictionary via Text Editor but after 
>>>an hour or so trial an error guessing what information the script 
>>>required with no success I am hoping to gather the experiences of 
>>>others.
>>>
>>>If any one could send me some example apple scripts or point me in 
>>>the right direction i would be most appreciative
>>>
>>>
>>>(on another note, having had a snoop through the post history, I 
>>>am impressed that Python functionality will be included in the 
>>>next version. Looking forward to checking this out!)
>>>
>>>
>>>cheers
>>>
>>>Nic
>>>
>>>from Oz
>>>
>>>in Zurich
>>>
>>>
>>>
>>>
>>>_______________________________________________
>>>proFit-list mailing list
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>>><http://quantum-soft.com/mailman/listinfo/profit-list_quantum-soft.com>http://quantum-soft.com/mailman/listinfo/profit-list_quantum-soft.com
>>>
>>
>>
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>
>
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