---------- Forwarded message ---------- From: Ahmed Attia <ahmedati...@gmail.com> Date: Mon, Jan 14, 2013 at 2:31 AM Subject: Help with nonlinear regression To: r-help@r-project.org
Dears- I have a question about nonlinear regression. Asymptotic Regression Model below is the equation of the model (Reference the R book page 662) y = a - b e^-cx when I compensate x with 50 for instance, I get a very high value does not match the graph produced by the same model (Asymptotic regression model). below is the output analysis from R; Formula: GN1 ~ SSasymp(nrate, a, b, c) Parameters: Estimate Std. Error t value Pr(>|t|) a 12.8190 0.4407 29.09 8.92e-05 *** b 5.7249 0.2803 20.42 0.000257 *** c -4.6697 0.1703 -27.41 0.000107 *** --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 Residual standard error: 0.2874 on 3 degrees of freedom Number of iterations to convergence: 0 Achieved convergence tolerance: 7.184e-06 > based on these coefficients should y= 12.81 – 5.72 e4.66x ? the predicted lines indicate that the model works fine, but I do not know how to compensate x in the equation to get y AA -- Ahmed M. Attia Research Assistant Dept. Of Soil&Crop Sciences Texas A&M University ahmed.at...@ag.tamu.edu Cell phone: 001-979-248-5215 ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
