Using nonlinear regression

Is there some reason you don't want to use maximum likelihood?  With 
the 2-parameter lognormal and no censored observations, the maximum 
likelihood estimates (MLEs) are just the mean and standard deviation of 
the logs.  See ?fitdistr in library(MASS).

	  If you really want nonlinear least squares, have you considered "nls"?

	  In the likely event that this response does not meet your needs, I 
suggest you consider preparing another question using the posting guide! 
http://www.R-project.org/posting-guide.html, as it can increase the 
chances of getting a more helpful reply -- if you don't find an answer 
in the course of preparing a question following the guide.

	  spencer graves

Hi, I have been trying to figure out how to use the nonlinear regression to 
fit the cumulative lognormal distribution to a number of data points I have 
but I am a new R user and I cant quite decipher the notes on nonlinear 
regression.  Any help in this regard will be greatly appreciated, my email 
address is mmiller at nassp.uct.ac.za

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Spencer Graves, PhD
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