[R] Optimization

[Simone Vincenzi]

Dear R-list,
I'm trying to estimate the relative importance of 6 environmental variables
in determining clam yield. To estimate clam yield a previous work used the
function Yield = (A^a*B^b*C^c...)^1/(a+b+c+...) where A,B,C... are the
values of the environmental variables and the weights a,b,c... have not been
calibrated on data but taken from literature. Now I'd like to estimate the
weights a,b,c... by using a dataset with 110 observations of yield and
values of the environmental variables. I'm wondering if it is feasible or if
the number of observation is too low, if some data transformation is needed
and which R function is the most appropriate to try to estimate the weights.
Any help would be greatly appreciated.

Simone Vincenzi 

_________________________________________
Simone Vincenzi, PhD Student 
Department of Environmental Sciences
University of Parma
Parco Area delle Scienze, 33/A, 43100 Parma, Italy
Phone: +39 0521 905696
Fax: +39 0521 906611
e.mail: svincenz at nemo.unipr.it 



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