On Mon, 2007-11-26 at 14:17 +0000, [EMAIL PROTECTED] wrote: > > Here are the codes of the example of lm( ): > > > > ## Annette Dobson (1990) "An Introduction to > > Generalized Linear Models". > > ## Page 9: Plant Weight Data. > > ctl <- > > (4.17,5.58,5.18,6.11,4.50,4.61,5.17,4.53,5.33,5.14) > > trt <- > > (4.81,4.17,4.41,3.59,5.87,3.83,6.03,4.89,4.32,4.69) > > group <- gl(2,10,20, labels=c("Ctl","Trt")) > > weight <- c(ctl, trt) > > anova(lm.D9 <- lm(weight ~ group)) > > lm.D90 <- lm(weight ~ group - 1) # omitting intercept > > > > What I am doing is let the variable name "group" > > stored in a vector, say, g <- "group". The question is > > how to strip the quotation marks when we call lm( ) > > through g? > > Try: > w = "weight" > g = "group" > form = as.formula(paste(w,g,sep="~")) > lm(form) > > Regards, > Richie.
For more complicated automation, the ideas and examples from Bill Venables Programmer Niche article in the R newsletter from a few years ago might be of use: [39] Bill Venables. Programmer's niche. R News, 2(2):24-26, June 2002. [ bib | PDF | http ] The PDF is available here: http://cran.r-project.org/doc/Rnews/Rnews_2002-2.pdf HTH G > > Mathematical Sciences Unit > HSL > > > ------------------------------------------------------------------------ > ATTENTION: > > This message contains privileged and confidential inform...{{dropped:20}} > > ______________________________________________ > 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. -- %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% Dr. Gavin Simpson [t] +44 (0)20 7679 0522 ECRC, UCL Geography, [f] +44 (0)20 7679 0565 Pearson Building, [e] gavin.simpsonATNOSPAMucl.ac.uk Gower Street, London [w] http://www.ucl.ac.uk/~ucfagls/ UK. WC1E 6BT. [w] http://www.freshwaters.org.uk %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% ______________________________________________ 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.