Hello.  I am trying to fit a non-rectangular hyperbola function to data
of photosynthetic rate vs. light intensity.  There are 4 parameters that
have to be estimated.  I find the nls function very difficult to use
because it often fails to converge and then gives out cryptic error
messages.  I have tried playing with the control parameters but this
does not always help.

Is there another non-linear regression function in R that I might try
(other than regression smoothers, which won’t give the parameter
estimates of the specified function)?

 

Bill Shipley

Subject Matter Editor, Ecology

North American Editor, Annals of Botany

Département de biologie, Université de Sherbrooke,

Sherbrooke (Québec) J1K 2R1 CANADA

Bill.Shipley@USherbrooke.ca

 <http://callisto.si.usherb.ca:8080/bshipley/>
http://callisto.si.usherb.ca:8080/bshipley/

 


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