> -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf Of stephen sefick > Sent: March-31-11 3:38 PM > To: R help > Subject: [R] Linear Model with curve fitting parameter? > > I have a model Q=K*A*(R^r)*(S^s) > > A, R, and S are data I have and K is a curve fitting parameter. I > have linearized as > > log(Q)=log(K)+log(A)+r*log(R)+s*log(S) > > I have taken the log of the data that I have and this is the model > formula without the K part > > lm(Q~offset(A)+R+S, data=x) > > What is the formula that I should use?
Let Z = Q - A for your logged data. Fitting lm(Z ~ R + S, data = x) should yield intercept parameter estimate = estimate for log(K) R coefficient parameter estimate = estimate for r S coefficient parameter estimate = estimate for s Steven McKinney Statistician Molecular Oncology and Breast Cancer Program British Columbia Cancer Research Centre > > Thanks for all of your help. I can provide a subset of data if necessary. > > > > -- > Stephen Sefick > ____________________________________ > | Auburn University | > | Biological Sciences | > | 331 Funchess Hall | > | Auburn, Alabama | > | 36849 | > |___________________________________| > | sas0...@auburn.edu | > | http://www.auburn.edu/~sas0025 | > |___________________________________| > > Let's not spend our time and resources thinking about things that are > so little or so large that all they really do for us is puff us up and > make us feel like gods. We are mammals, and have not exhausted the > annoying little problems of being mammals. > > -K. Mullis > > "A big computer, a complex algorithm and a long time does not equal science." > > -Robert Gentleman > ______________________________________________ > 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. ______________________________________________ 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.
