looks to me like a problem for -nl-, see: -help nl-
Hope this helps,
Maarten
--- Tobias Pfaff <[email protected]> wrote:
> Hi,
>
> for given data points I want to find out a parameter for a function
> such
> that the function fits best to the data points.
> The function would be: f(x)=x^alpha.
> The data points are:
>
> x_values y_values
> -------- --------
> 0,0000 0
> 0,0156 0,45
> 0,0313 0,52
> 0,0625 4,83
> 0,0938 11,66
> 0,1250 12,79
> 0,1875 21,5
> 0,2188 25,69
> 0,2344 27,89
> 0,2500 29,93
>
> I know how I could do that with the least square method and the Excel
> solver.
> Which Stata command would deliver the same result? Is _reg3_ the
> appropriate
> command? How would the command line look like?
>
> Furthermore, I want to do the same with 2 unknown parameters, e.g.
> for the
> function f(x)=-k*(-x)^alpha. Which command would be appropriate for 2
> unknown parameters (here: k and alpha)?
>
> Any comments would be greatly appreciated.
>
> Cheers,
> Tobias Pfaff
>
> University of Muenster
> Germany
>
> *
> * For searches and help try:
> * http://www.stata.com/support/faqs/res/findit.html
> * http://www.stata.com/support/statalist/faq
> * http://www.ats.ucla.edu/stat/stata/
>
-----------------------------------------
Maarten L. Buis
Department of Social Research Methodology
Vrije Universiteit Amsterdam
Boelelaan 1081
1081 HV Amsterdam
The Netherlands
visiting address:
Buitenveldertselaan 3 (Metropolitan), room Z434
+31 20 5986715
http://home.fsw.vu.nl/m.buis/
-----------------------------------------
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