> I have two variables X and Y, and think that Y is related > to X by a function of the form : Y = X^Z, where Z is < 1. > However, I'm not sure how to find the best-fit equation to > fit my data to a curve of this form using R. Have you any ideas?
You can use nlm() to fit a non-linear model. Another option would be to fit a linear model to log-log transformed data. However, if you are actually trying to fit to a power-law distribution you may want to have a look at these references: Goldstein, M.; Morris, S. & Yen, G. Problems with Fitting to the Power-Law Distribution European Physical Journal B, 2004, 41, 255-258 Newman, M. E. J. Power laws, Pareto distributions and Zipf's law Contemporary Physics, 2005, 46, 323 cu Philipp -- Dr. Philipp Pagel Lehrstuhl für Genomorientierte Bioinformatik Technische Universität München Wissenschaftszentrum Weihenstephan 85350 Freising, Germany http://mips.gsf.de/staff/pagel ______________________________________________ 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.